ASSIGNMENT, ASSUMPTION AND RECOGNITION AGREEMENT

Exhibit 99.9(a)

EXECUTION COPY




ASSIGNMENT, ASSUMPTION AND RECOGNITION AGREEMENT

THIS ASSIGNMENT, ASSUMPTION AND RECOGNITION AGREEMENT (this
"Assignment"), dated of December 1, 2006, is entered into among Morgan Stanley
Capital I Inc., a Delaware corporation (the "Depositor"), Morgan Stanley
Mortgage Capital Inc. ("MSMCI"), IndyMac Bank, F.S.B., as seller (in such
capacity, the "Seller") and as servicer (in such capacity, the "Servicer"),
LaSalle Bank National Association ("LaSalle"), as trustee ("Trustee"), of
Morgan Stanley Mortgage Loan Trust 2006-17XS (the "Trust"), and acknowledged
by Wells Fargo Bank, National Association, as master servicer (in such
capacity, the "Master Servicer") and as securities administrator (in such
capacity, the "Securities Administrator").

RECITALS

WHEREAS MSMCI, the Seller and the Servicer have entered into (a) a
certain Mortgage Loan Purchase and Warranties Agreement, dated as of September
1, 2006 (as amended or modified to the date hereof, the "Sale Agreement") and
(b) a certain Servicing Agreement, dated as of September 1, 2006 (as amended
or modified to the date hereof, the "Servicing Agreement" and, together with
the Sale Agreement, the "Agreements"), pursuant to which MSMCI has acquired
certain Mortgage Loans pursuant to the terms of the Sale Agreement and the
Servicer has agreed to service such Mortgage Loans pursuant to the terms of
the Servicing Agreement;

WHEREAS the Depositor has agreed, on the terms and conditions
contained herein, to purchase from MSMCI certain of the Mortgage Loans (the
"Specified Mortgage Loans") which are subject to the provisions of the
Agreements and are listed on the mortgage loan schedule attached as Exhibit I
hereto (the "Specified Mortgage Loan Schedule"); and

WHEREAS the Trustee, on behalf of the Trust, has agreed, on the terms
and conditions contained herein, to purchase from the Depositor the Specified
Mortgage Loans;

NOW, THEREFORE, in consideration of the mutual promises contained
herein and other good and valuable consideration (the receipt and sufficiency
of which are hereby acknowledged), the parties agree as follows:

1. Assignment and Assumption

(a) On and as of the date hereof, MSMCI hereby sells, assigns and
transfers to the Depositor all of its right, title and interest in the
Specified Mortgage Loans and all rights and obligations related thereto as
provided under the Agreement to the extent relating to the Specified Mortgage
Loans, the Depositor hereby accepts such assignment from MSMCI (the "First
Assignment and Assumption"), and the Seller hereby acknowledges the First
Assignment and Assumption.

MSMCI specifically reserves and does not assign to the Depositor
hereunder any and all right, title and interest in, to and under and all
obligations of MSMCI with respect to any Mortgage Loans subject to the
Agreement which are not the Specified Mortgage Loans.


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(b) On and as of the date hereof, immediately after giving effect to
the First Assignment and Assumption, the Depositor hereby sells, assigns and
transfers to the Trustee, on behalf of the Trust, all of its right, title and
interest in the Specified Mortgage Loans and all rights and obligations
related thereto as provided under the Agreements to the extent relating to the
Specified Mortgage Loans, and the Trustee, on behalf of the Trust, hereby
accepts such assignment from the Depositor (the "Second Assignment and
Assumption"), and the Seller hereby acknowledges the Second Assignment and
Assumption.

(c) On and as of the date hereof, MSMCI represents and warrants to
the Depositor and the Trustee that MSMCI has not taken any action that would
serve to impair or encumber the respective ownership interests of the
Depositor and the Trustee in the Specified Mortgage Loans since the date of
MSMCI's acquisition of the Specified Mortgage Loans.

2. Recognition of Trustee

(a) From and after the date hereof, both MSMCI and the Seller shall
note the transfer of the Specified Mortgage Loans to the Trustee, in their
respective books and records and shall recognize the Trustee, on behalf of the
Trust, as of the date hereof, as the owner of the Specified Mortgage Loans,
and Servicer shall service the Specified Mortgage Loans for the benefit of the
Trust pursuant to the Servicing Agreement, the terms of which are incorporated
herein by reference. It is the intention of the Seller, the Servicer, the
Depositor, the Trustee and MSMCI that this Assignment shall be binding upon
and inure to the benefit of the Depositor, the Trustee and MSMCI and their
respective successors and assigns.

(b) Without in any way limiting the foregoing, the parties confirm
that this Assignment includes the rights relating to amendments or waivers
under the Agreements. Accordingly, the right of MSMCI to consent to any
amendment of the Agreement and its rights concerning waivers as set forth in
Section 23 of the Sale Agreement and Section 11.02 of the Servicing Agreement
shall be exercisable, to the extent any such amendment or waiver affects the
Specified Mortgage Loans or any of the rights under the Agreement with respect
thereto (other than the servicing of the Specified Mortgage Loans, which shall
be enforced by the Master Servicer) by the Trustee as assignee of MSMCI.

(c) It is expressly understood and agreed by the parties hereto that
(i) this Assignment is executed and delivered by LaSalle Bank National
Association, not individually or personally but solely on behalf of the Trust,
as the assignee, in the exercise of the powers and authority conferred and
vested in it, as Trustee, pursuant to the Pooling and Servicing Agreement
dated as of the date hereof among the Depositor, the Master Servicer, Wells
Fargo Bank, National Association, as securities administrator (the "Securities
Administrator") and the Trustee (the "Pooling and Servicing Agreement"), (ii)
each of the representations, undertakings and agreements herein made on the
part of assignee is made and intended not as personal representations,
undertakings and agreements by LaSalle Bank National Association but is made
and intended for the purpose of binding only the Trust , (iii) nothing herein
contained shall be construed as creating any liability for LaSalle Bank
National Association, individually or personally, to perform any covenant
(either express or implied) contained herein and (iv) under no circumstances
shall LaSalle Bank National Association be personally liable for the payment
of any indebtedness or expenses of the Trust, or be liable for the breach or
failure of any



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obligation, representation, warranty or covenant made or undertaken by the
Trust under this Assignment and (v) all recourse for any payment liability or
other obligation of the assignee shall be had solely to the assets of the
Trust.


3. Representations and Warranties

(a) The Depositor represents and warrants that it is a sophisticated
investor able to evaluate the risks and merits of the transactions
contemplated hereby, and that it has not relied in connection therewith upon
any statements or representations of the Seller or MSMCI other than those
contained in the Agreements or this Assignment.

(b) Each of the parties hereto represents and warrants that it is
duly and legally authorized to enter into this Assignment.

(c) Each of the parties hereto represents and warrants that this
Assignment has been duly authorized, executed and delivered by it and
(assuming due authorization, execution and delivery thereof by each of the
other parties hereto) constitutes its legal, valid and binding obligation,
enforceable against it in accordance with its terms, except as such
enforcement may be limited by bankruptcy, insolvency, reorganization or other
similar laws affecting the enforcement of creditors' rights generally and by
general equitable principles (regardless of whether such enforcement is
considered in a proceeding in equity or at law).

(d) The Seller hereby restates, as of December 28, 2006 (the "Closing
Date"), the representations and warranties set forth in Sections 9.01 and 9.02
of the Sale Agreement, with respect to each of the Specified Mortgage Loans
that were sold by it under the Sale Agreement, to and for the benefit of the
Depositor, the Trustee and the Trust, and by this reference incorporates such
representations and warranties herein, as of such date.

(e) The Servicer hereby restates, as of the Closing Date, the
representations and warranties set forth in Articles X and XIII of the
Servicing Agreement, with respect to each of the Specified Mortgage Loans it
agreed to service under the Servicing Agreement, to and for the benefit of the
Depositor, the Trustee and the Trust, and by this reference incorporates such
representations and warranties herein, as of such Closing Date.

(f) The Servicer hereby represents and warrants to the Trustee that,
to the extent the Mortgage Loans will be part of a REMIC, the Servicer shall
service the Mortgage Loans and any real property acquired upon default thereof
(including, without limitation, making or permitting any modification, waiver
or amendment of any term of any Mortgage Loan) in accordance with the
Servicing Agreement, but in no event in a manner that would (a) cause the
REMIC to fail or qualify as a REMIC or (b) result in the imposition of a tax
upon the REMIC (including, but not limited to, the tax on prohibited
transactions as defined in Section 860F(a)(2) of the Code, the tax on
contributions to a REMIC set forth in Section 860G(d) of the Code and the tax
on "net income from foreclosure property" as set forth in Section 860G(c) of
the Code).



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4. The Servicer hereby acknowledges that Wells Fargo Bank, National
Association has been appointed as the Master Servicer of the Specified
Mortgage Loans pursuant to the Pooling and Servicing Agreement and, therefore,
has the right to enforce all obligations of the Servicer under the Servicing
Agreement. Such rights will include, without limitation, the right to
terminate the Servicer under the Servicing Agreement upon the occurrence of an
event of default thereunder, the right to receive all remittances required to
be made by the Servicer under the Servicing Agreement, the right to receive
all monthly reports and other data required to be delivered by the Servicer
under the Servicing Agreement, the right to examine the books and records of
the Servicer, indemnification rights and the right to exercise certain rights
of consent and approval of MSMCI. The Servicer shall make all distributions
under the Servicing Agreement to the Master Servicer by wire transfer of
immediately available funds to:

Wells Fargo Bank, National Association
ABA Number: 121-000-248
Account Name: Corporate Trust Clearing
Account number: 3970771416
For further credit to: 50973800, MSM 2006-17XS

The Servicer shall deliver all reports required to be delivered under
the Agreement to the Master Servicer at the following address:

Wells Fargo Bank, National Association
9062 Old Annapolis Road
Columbia, Maryland 21045
Attention: Client Manager, MSM 2006-17XS
Telecopier: (410) 715-2380

5. Amendments to the Servicing Agreement

The parties to this Assignment hereby agree to amend the Servicing
Agreement as follows:

(a) With respect to the Specified Mortgage Loans, "Permitted
Investments" shall have the meaning of such term as defined in
the Pooling and Servicing Agreement.

(b) The definition of "Eligible Account" is hereby inserted into
Section 1.01:

"Eligible Account: Any of (i) an account or accounts maintained with
a federal or state chartered depository institution or trust company, the
short-term unsecured debt obligations of which (or, in the case of a
depository institution or trust company that is the principal subsidiary of a
holding company, the debt obligations of such holding company) have the
highest short-term ratings of Moody's or Fitch and one of the two highest
short-term ratings of S&P, if S&P is a Rating Agency, at the time any amounts
are held on deposit therein, or (ii) an account or accounts in a depository
institution or trust company in which such accounts are insured by the FDIC
(to the limits established by the FDIC) and the uninsured deposits in which
accounts are otherwise secured such that, as evidenced by an Opinion of
Counsel delivered to the Trustee and to each Rating Agency, the
Certificateholders have a claim with respect to the funds in such



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account or a perfected first priority security interest against any collateral
(which shall be limited to Permitted Investments) securing such funds that is
superior to claims of any other depositors or creditors of the depository
institution or trust company in which such account is maintained, or (iii) a
trust account or accounts maintained with (a) the trust department of a
federal or state chartered depository institution or (b) a trust company,
acting in its fiduciary capacity or (iv) any other account acceptable to each
Rating Agency."

(c) The definition of "Remittance Date" in Section 1.01 is
hereby amended and restated in its entirety as follows:

"Remittance Date: No later than 1:00 p.m. New York time on the 18th
day of each month (or, if such 18th day is not a Business Day, the following
Business Day) beginning with the first Remittance Date after the Closing
Date."

(d) The definition of "Servicing Fee" in Section 1.01 is hereby
amended and restated in its entirety as follows:

"Servicing Fee: With respect to each Mortgage Loan subject to this
Agreement, an amount equal to one-twelfth of the product of (a) the Servicing
Fee Rate and (b) the scheduled principal balance of such Mortgage Loan payable
monthly. Such fee shall be payable monthly. The obligation of the Purchaser to
pay the Servicing Fee is limited to, and the Servicing Fee is payable solely
from, the interest portion (including recoveries with respect to interest from
Liquidation Proceeds, to the extent permitted by Section 4.03) of such Monthly
Payment collected by the Servicer, or as otherwise provided under Section
4.03."

(e) With respect to each Specified Mortgage Loan, the definition
of "Servicing Fee Rate" in Section 1.01 is hereby amended and
restated in its entirety as follows:

"Servicing Fee Rate: 25 basis points (0.25%) per annum."

(f) The second and third sentences of the first paragraph of
Section 2.04 are amended and restated in their entirety as
follows:

"The Custodial Account shall be an Eligible Account established with
a Qualified Depository acceptable to the Purchaser. Any funds deposited in the
Custodial Account shall at all times be fully insured."

(g) The second sentence of the last paragraph of Section 2.04 is
amended and restated in its entirety as the following two
sentences:

"The Servicer may at its option invest the amounts on deposit in the
Custodial Account in Permitted Investments. Any income from Permitted
Investments paid on funds deposited in the Custodial Account by the depository
institution shall accrue to the benefit of the Servicer and the Servicer shall
be entitled to retain and withdraw such interest from the Custodial Account
pursuant to Section 2.05."

(h) The word "and" is deleted from the end of Section 2.05(iii)
of each Agreement, the word "and" is added at the end of Section
2.05(iv) of each Agreement and the following paragraph is hereby
incorporated into each Agreement as new Section 2.05(v):



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"to reimburse itself for unreimbursed Servicing Advances and
unreimbursed advances made in accordance with Section 3.03, to the extent that
such amounts are nonrecoverable by the Servicer pursuant to subclause (ii)
above, provided that the Mortgage Loan for which such advances were made is
not required to be repurchased by the Seller pursuant to Section 9.03 of the
Sale Agreement."

(i) The second and third paragraphs of Section 2.16 of the
Servicing Agreement are hereby amended and restated in their
entirety as follows:

"With respect to any REO Property, the deed or certificate of sale
shall be taken in the name of the Purchaser, or its designee. The Trustee's
name shall be placed on the title to such REO Property solely as the Trustee
hereunder and not in its individual capacity. The Servicer shall ensure that
the title to such REO Property references the Agreement and the Purchaser's
capacity thereunder. Pursuant to its efforts to sell such REO Property, the
Servicer shall either itself or through an agent selected by the Servicer
protect and conserve such REO Property in the same manner and to such extent
as is customary in the locality where such REO Property is located and may,
incident to its conservation and protection of the interests of the Purchaser,
or its designee, rent the same, or any part thereof, as the Servicer deems to
be in the best interest of the Purchaser, or its designee, for the period
prior to the sale of such REO Property. The Servicer shall prepare for and
deliver to the Purchaser, or its designee, a statement with respect to each
REO Property that has been rented showing the aggregate rental income received
and all expenses incurred in connection with the maintenance of such REO
Property at such times as is necessary to enable the Purchaser, or its
designee, to comply with the reporting requirements of the REMIC Provisions.
The net monthly rental income, if any, from such REO Property shall be
deposited in the Certificate Account no later than the close of business on
each Determination Date. The Servicer shall perform the tax reporting and
withholding required by Sections 1445 and 6050J of the Code with respect to
foreclosures and abandonments, the tax reporting required by Section 6050H of
the Code with respect to the receipt of mortgage interest from individuals and
any tax reporting required by Section 6050P of the Code with respect to the
cancellation of indebtedness by certain financial entities, by preparing such
tax and information returns as may be required, in the form required, and
delivering the same to the Purchaser, or its designee, for filing.

In the event that the Purchaser, or its designee, acquires any
Mortgaged Property as aforesaid or otherwise in connection with a default or
imminent default on a Mortgage Loan, the Servicer shall dispose of such
Mortgaged Property as soon as practicable in a manner that maximizes the
Liquidation Proceeds thereof, but in no event later than three years after its
acquisition by the Purchaser, or its designee. In that event, the Purchaser,
or its designee, shall have been supplied with an Opinion of Counsel to the
effect that the holding by the Purchaser, or its designee, of such Mortgaged
Property subsequent to a three-year period, if applicable, will not result in
the imposition of taxes on "prohibited transactions" of any REMIC as defined
in section 860F of the Code or cause any REMIC to fail to qualify as a REMIC
at any time, the Purchaser, or its designee, may continue to hold such
Mortgaged Property (subject to any conditions contained in such Opinion of
Counsel) after the expiration of such three-year period. Notwithstanding any
other provision of this Agreement, no Mortgaged Property acquired by the
Purchaser, or its designee, shall be rented (or allowed to continue to be
rented) or otherwise used for the production of income by or on behalf of the
Purchaser, or its designee, in such a manner or pursuant to any terms that
would (i) cause such Mortgaged Property to fail to qualify as



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"foreclosure property" within the meaning of section 860G(a)(8) of the Code or
(ii) subject any REMIC to the imposition of any federal, state or local income
taxes on the income earned from such Mortgaged Property under Section 860G(c)
of the Code or otherwise, unless the Servicer has agreed to indemnify and hold
harmless the Purchaser, or its designee, with respect to the imposition of any
such taxes."

(j) The first sentence of Section 2.18 of the Servicing
Agreement is hereby amended to replace the words "Business Day
of each month" with the words "calendar day of each month (or,
if such 10th day is not a Business Day, the following Business
Day)"

(k) The first paragraph of Section 3.02 of the Servicing
Agreement is hereby amended and restated in its entirety as
follows:

"Each month, no later than the 10th calendar day of each month, the
Servicer shall furnish to the Master Servicer a remittance report, in the form
of Exhibit II hereto (the "Remittance Report"), and such other mortgage loan
level data or information as mutually agreed upon by the Servicer and the
Master Servicer, in electronic format acceptable to the Master Servicer, in
each case with respect to funds being remitted to the Master Servicer on the
related Remittance Date."

(l) The second paragraph of Section 3.01 of the Servicing
Agreement is hereby amended and restated in its entirety as
follows:

"With respect to any funds deposited in the Custodial Account after
the Business Day on which such deposit was required to be made, the Servicer
shall pay to the Purchaser interest on any such late payment at an annual rate
equal to the Prime Rate, adjusted as of the date of each change, plus two
percentage points, but in no event greater than the maximum amount permitted
by applicable law. Such interest shall be deposited in the Custodial Account
by the Servicer on the date such late payment is made and shall cover the
period commencing with such Business Day and ending with the Business Day on
which such payment is made, both inclusive. The payment by the Servicer of any
such interest shall not be deemed an extension of time for payment or a waiver
of any Event of Default by the Servicer."

(m) Section 3.03 of the Servicing Agreement is hereby amended
and restated in its entirety as follows:

"Advances by Servicer. On the Business Day immediately preceding each
Remittance Date, the Servicer shall (a) deposit in the Custodial Account from
its own funds an amount equal to all Monthly Payments which were due on the
Mortgage Loans during the applicable Due Period and which were delinquent at
the close of business on the immediately preceding Determination Date or which
were deferred pursuant to Section 2.01, (b) cause to be made an appropriate
entry in the records of the Custodial Account that amounts held for future
distribution have been, as permitted by this Section 3.03, used by the
Servicer in discharge of any such advance or (c) make advances in the form of
any combination of (a) or (b) aggregating the total amount of advances to be
made. The Servicer's obligation to make such advances as to any Mortgage Loan
will continue through the earlier to occur of (a) the last Monthly Payment due
prior to the payment in full of the Mortgage Loan or (b) the last Remittance
Date prior to the Remittance Date for the distribution of all Liquidation
Proceeds and other payments or recoveries (including Insurance Proceeds, and
Condemnation Proceeds) with respect to the

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Mortgage Loan; provided, however, that such obligation shall cease if the
Servicer, in its good faith judgment, determines that an advance would not be
recoverable pursuant to Section 2.05(ii). The determination by the Servicer
that an advance, if made, would be nonrecoverable, shall be evidenced by an
Officer's Certificate of the Servicer, delivered to the Purchaser, which
details the reasons for such determination. To the extent permitted under
Section 2.05 hereof, the Servicer shall be entitled to first priority
reimbursement for principal and interest advances and for Servicing Advances
from recoveries from the related Mortgagor or from all Liquidation Proceeds
and other payments or recoveries (including Insurance Proceeds and
Condemnation Proceeds) with respect to the related Mortgage Loan."

(n) Sections 4.04 and 4.05 of the Servicing Agreement are hereby
deleted.

(o) the following paragraph is hereby incorporated into the
Servicing Agreement as new Section 11.01(h):

"(h) failure by the Servicer to duly perform, within the required
time period, its obligations under Sections 13.04 and 13.05 which failure
continues unremedied for a period of fourteen (14) days;"

(p) The following paragraph is hereby incorporated into the
Servicing Agreement as new Section 12.16:

"Third Party Beneficiary. For purposes of this Agreement, including
but not limited to Sections 13.04 and 13.05, any Master Servicer shall be
considered a third party beneficiary to this Agreement entitled to all the
rights and benefits accruing to any Master Servicer herein as if it were a
direct party to this Agreement. In addition, a copy of all assessments,
attestations, reports and certifications required to be delivered by the
Servicer under this Agreement and the Servicing Agreement shall be delivered
to the Master Servicer by the date(s) specified herein or therein, and where
such documents are required to be addressed to any party, such addressees
shall include the Master Servicer and the Master Servicer shall be entitled to
rely on such documents."

(q) Section 13.03(d) of the Servicing Agreement is hereby amended and
restated in its entirety as follows:

"(d) For the purpose of satisfying the reporting obligation
under the Exchange Act with respect to any class of asset-backed
securities, each Seller and the Servicer shall (or shall cause
each Subservicer and Third-Party Originator to) (i) provide
prompt notice to the Purchaser, any Master Servicer and any
Depositor in writing of (A) any material litigation or
governmental proceedings involving the Servicer, any Subservicer
or any Third-Party Originator, (B) any affiliations or
relationships that develop following the closing date of a
Securitization Transaction between the Servicer, any Subservicer
or any Third-Party Originator and any of the parties specified
in clause (D) of paragraph (a) of this Section (and any other
parties identified in writing by the requesting party) with
respect to such Securitization Transaction, (C) any Event of
Default under the terms of this Agreement or any Reconstitution
Agreement, (D) any merger, consolidation or sale of
substantially all of the assets of the Servicer, and (E) the
Servicer's entry into an agreement with a Subservicer to perform
or assist in the performance of



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any of the Servicer's obligations under this Agreement or any
Reconstitution Agreement and (ii) provide to the Purchaser and
any Depositor a description of such proceedings, affiliations or
relationships."

(r) Section 13.03(f) of the Servicing Agreement is hereby amended and
restated in its entirety as follows:

"(f) In addition to such information as the Servicer, as
servicer, is obligated to provide pursuant to other provisions
of this Agreement, not later than ten days prior to the deadline
for the filing of any distribution report on Form 10-D in
respect of any Securitization Transaction that includes any of
the Mortgage Loans serviced by the Servicer or any Subservicer,
the Servicer or such Subservicer, as applicable, shall, to the
extent the Servicer or such Subservicer has knowledge, provide
to the party responsible for filing such report (including, if
applicable, the Master Servicer) notice of the occurrence of any
of the following events along with all information, data, and
materials related thereto as may be required to be included in
the related distribution report on Form 10-D (as specified in
the provisions of Regulation AB referenced below):

(i) any material modifications, extensions or waivers
of pool asset terms, fees, penalties or payments during
the distribution period or that have cumulatively become
material over time (Item 1121(a)(11) of Regulation AB);

(ii) material breaches of pool asset representations
or warranties or transaction covenants (Item 1121(a)(12)
of Regulation AB); and

(iii) information regarding new asset-backed
securities issuances backed by the same pool assets, any
pool asset changes (such as, additions, substitutions or
repurchases), and any material changes in origination,
underwriting or other criteria for acquisition or
selection of pool assets (Item 1121(a)(14) of Regulation
AB).

(g) The Servicer shall provide to the Purchaser, any Master
Servicer and any Depositor, evidence of the authorization of the
person signing any certification or statement, copies or other
evidence of Fidelity Bond Insurance and Errors and Omission
Insurance policy, financial information and reports, and such
other information related to the Servicer or any Subservicer or
the Servicer or such Subservicer's performance hereunder."

(s) Section 13.05(a)(iv) of the Servicing Agreement is hereby amended
and restated in its entirety as follows:

"(iv) deliver, and cause each subservicer and subcontractor
described in clause (iii) above to deliver, to the Purchaser, any
Depositor and any other Person that will be responsible for signing
the certification (a "Sarbanes Certification") required by Rules
13a-14(d) and 15d-14(d) under the Exchange Act (pursuant to Section
302 of the Sarbanes-Oxley Act of 2002) on behalf of an asset-backed
issuer with respect to a



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Securitization Transaction a certification, signed by an appropriate
officer of the Servicer, in the form attached hereto as Exhibit 7."

(t) Section 13.06(a) of the Servicing Agreement is hereby amended to
add Sections 13.03(f) and 13.03(g) as provisions that the
Subservicers must comply with to same extent as if such Subservicer
were the Servicer.

(u) The last sentence of the last paragraph of Section 13.06 of the
Servicing Agreement is amended to require the Servicer to cause any
Subservicer or Subcontractor to provide any assessment of compliance
and attestation but also any other certifications required to
delivered under this Section 13.06.

(v) Section 13.07(a)(ii) of the Servicing Agreement is hereby amended
and restated in its entirety as follows:

"(ii) any breach by the Seller or Servicer under, or any
failure by any Seller, the Servicer, any Subservicer, any
Subcontractor or any Third-Party Originator to deliver any
information, report, certification, accountants' letter or other
material when and as required, under this Article XIII, including any
failure by the Servicer to identify pursuant to Section 13.06(b) any
Subcontractor "participating in the servicing function" within the
meaning of Item 1122 of Regulation AB;"

(w) The word "or" is struck at the end of Section 13.07(a)(ii) of the
Servicing Agreement and the following is inserted to Section 13.07(a)
of the Servicing Agreement:

"(iv) negligence, bad faith or willful misconduct of the
Servicer in connection with its performance under this Article XIII.

If the indemnification provided for herein is unavailable or
insufficient to hold harmless an Indemnified Party, then the Servicer
agrees that it shall contribute to the amount paid or payable by such
Indemnified Party as a result of any claims, losses, damages or
liabilities incurred by such Indemnified Party in such proportion as
is appropriate to reflect the relative fault of such Indemnified
Party on the one hand and the Servicer on the other.

This indemnification shall survive the termination of this
Agreement or the termination of any party to this Agreement."

(x) The following parenthetical is inserted directly before the
proviso in the last sentence of the first paragraph of Section
13.07(b)(i) of the Servicing Agreement:

(y) "(and if the Servicer is servicing any of the Mortgage Loans
in a Securitization Transaction, appoint a successor servicer
reasonably acceptable to the Master Servicer for such
Securitization Transaction)"

(z) Exhibit 1 to the Servicing Agreement is hereby deleted and
replaced with Exhibit II to this Assignment.

(aa) Exhibit 7 to the Servicing Agreement is hereby deleted and
replaced with Exhibit III to this Assignment.



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(bb) Exhibit 8 to the Servicing Agreement is hereby deleted and
replaced with Exhibit IV to this Assignment.

(cc) Written notice provided in compliance with Sections
13.03(d), (e) or (f) of the Servicing Agreement shall be
substantially in the form of Exhibit V to this Assignment.

6. Indemnification

The Master Servicer shall indemnify and hold harmless the Servicer
and its affiliates, and in each case, its officers, directors and agents from
and against any losses, damages, penalties, fines, forfeitures, reasonable
legal fees and related costs, judgments and other costs and expenses arising
out of or based upon a breach by the Master Servicer or any of its officers,
directors, agents or affiliates of its obligations in connection with the
preparation, filing and certification of any Form 10-K pursuant to the Pooling
and Servicing Agreement or the negligence, bad faith or willful misconduct of
the Master Servicer in connection therewith. In addition, the Master Servicer
shall indemnify and hold harmless the Servicer and its affiliates, and in each
case, its officers, directors and agents from and against any losses, damages,
penalties, fines, forfeitures, reasonable legal fees and related costs,
judgments and other costs and expenses arising out of or based upon a breach
by any Servicer (as defined in the Pooling and Servicing Agreement), other
than the Servicer (as defined herein), of its obligations in connection with
any back-up certification (or any other back-up documents) to any
certification of any Form 10-K required to be provided by the Master Servicer,
but solely to the extent the Master Servicer receives amounts from such
Servicer in connection with any indemnification provided by such Servicer (in
each case as defined in the Pooling and Servicing Agreement) to the Master
Servicer.

7. Continuing Effect

Except as contemplated hereby, the Agreements shall remain in full
force and effect in accordance with their terms.

8. Governing Law

This Assignment and the rights and obligations hereunder shall be
governed by and construed in accordance with the internal laws of the State of
New York.

9. Notices

Any notices or other communications permitted or required under the
Agreements to be made to the Depositor, MSMCI, the Master Servicer, the
Seller, the Servicer and the Trustee shall be made in accordance with the
terms of the Agreements and shall be sent to the Depositor and Trustee as
follows:

In the case of MSMCI:

Morgan Stanley Mortgage Capital Inc.
1221 Avenue of the Americas
New York, New York 10020


11
<PAGE>

Attention: Morgan Stanley Mortgage Loan Trust 2006-17XS

With a copy to:

Morgan Stanley & Co. Incorporated
1585 Broadway
New York, New York 10036
Attention: General Counsel's Office

In the case of the Depositor:

Morgan Stanley Capital I Inc.
1585 Broadway
New York, New York 10036
Attention: Morgan Stanley Mortgage Loan Trust 2006-17XS

In the case of the Trustee:

LaSalle Bank National Association
135 South LaSalle Street, Suite 1511
Chicago, Illinois 60603
Attention: Global Securities and Trust Services MSM 2006-17XS

In the case of the Seller and the Servicer:

IndyMac Bank, F.S.B.
3465 E. Foothill Boulevard
Pasadena, California 91107
Attention: Secondary Marketing

or to such other address as may hereafter be furnished by the Depositor and
the Trustee to the parties in accordance with the provisions of the
Agreements.

10. Ratification

Except as modified and expressly amended by this Assignment, the
Agreements are in all respects ratified and confirmed, and all terms,
provisions and conditions thereof shall be and remain in full force and
effect.

11. Counterparts

This Assignment may be executed in counterparts, each of which when
so executed shall be deemed to be an original and all of which when taken
together shall constitute one and the same instrument.

12. Definitions



12
<PAGE>

Any capitalized term used but not defined in this Assignment has the
same meaning as in the Agreements.

[SIGNATURE PAGE FOLLOWS]





13
<PAGE>

IN WITNESS WHEREOF, the parties hereto have
executed this Assignment the day and year first above written.

MORGAN STANLEY MORTGAGE CAPITAL INC.


By: /s/ VALERIE KAY
___________________________________________
Name: VALERIE KAY
Title: VICE PRESIDENT


MORGAN STANLEY CAPITAL I INC.


By: /s/ VALERIE KAY
___________________________________________
Name: VALERIE KAY
Title: VICE PRESIDENT



INDYMAC BANK, F.S.B.


By: /s/ JILL JACOBSON
___________________________________________
Name: JILL JACOBSON
Title: VICE PRESIDENT




Acknowledged and Agreed:
WELLS FARGO BANK, NATIONAL
ASSOCIATION, as Master Servicer


By: /s/ PATRICIA RUSSO
----------------------------------
Name: PATRICIA RUSSO
Title: VICE PRESIDENT

LASALLE BANK, NATIONAL
ASSOCIATION, as Trustee of Morgan Stanley
Mortgage Loan Trust 2006-17XS




<PAGE>

By: /s/ SUSAN L. FELD
----------------------------------
Name: SUSAN L. FELD
Title: ASSISTANT VICE PRESIDENT





<PAGE>

EXHIBIT I

Mortgage Loan Schedule

[see Schedule A to Pooling and Servicing Agreement]

Exhibit IIA: Standard File Layout - Delinquency Reporting
<TABLE>
<CAPTION>

---------------------------------------- -------------------------------------------------------------- ----------- ----------------
Column/Header Name Description Decimal Format
Comment
---------------------------------------- -------------------------------------------------------------- ----------- ----------------
<S> <C> <C> <C>
SERVICER_LOAN_NBR A unique number assigned to a loan by the Servicer. This
may be different than the LOAN_NBR
---------------------------------------- -------------------------------------------------------------- ----------- ----------------
LOAN_NBR A unique identifier assigned to each loan by the originator.
---------------------------------------- -------------------------------------------------------------- ----------- ----------------
CLIENT_NBR Servicer Client Number
---------------------------------------- -------------------------------------------------------------- ----------- ----------------
SERV_INVESTOR_NBR Contains a unique number as assigned by an external servicer
to identify a group of loans in their system.
---------------------------------------- -------------------------------------------------------------- ----------- ----------------
BORROWER_FIRST_NAME First Name