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HSRP and EIGRP. Do I need MHSRP?

Please draw as you read. It may seem complex but is a very simple problem.

EQUIPMENT:

------------------

PIX with 2 interfaces,

12-port Switch (Sa),

12-port Switch (Sb),

RouterA (Ra) with 2 Ethernet and 1 serial interfaces,

RouterB (Rb) with 2 Ethernet and 2 serial interfaces.

CONNECTIVITY:

----------------------

Sa and Sb connect to each other

Sa connects to E0/0 of Ra

Sb connects to E0/0 of Rb

Pix's outside connects to Sa

Ra and Rb are connected using cross-over via their E0/1

Ra's serial port is conencted to Site A

Rb's serial port 1 is connected to Site A and serial port 2 is connected to site B

Both switches and Routers are outside the firewall.

IP and ROUTING:

-----------------------

Ra and Rb run EIGRP with remote routers that belong to someone else. All routers are in the same AS 1.

Site A is one network say, 10.1.1.x, Site B is another network say 20.1.1.x. Both connect to each other as well, for redundancy, forming a typical ring with my outside routers.

QUESTIONS:

-----------------

Q1. Should I define two HSRP groups so that my PIX gets two outside gateways and sends data destined for Site A to Ra and data for site B to Rb.

Q2. If I only define one HSRP group, wont EIGRP anyways direct all traffic destined to SiteB to Rb?

Q3. Is there any advantage I will get if I decide to run MHSRP or I am just making my network unnecessarily complex?

Thanks.

1 ACCEPTED SOLUTION

Accepted Solutions
Silver

Re: HSRP and EIGRP. Do I need MHSRP?

ANSWERS:

Q1. Should I define two HSRP groups so that my PIX gets two outside gateways and sends data destined for Site A to Ra and data for site B to Rb.

Yes. No reason not to and no reason to incur extra hops which are not needed.

Q2. If I only define one HSRP group, wont EIGRP anyways direct all traffic destined to SiteB to Rb?

Yes. Assuming you have configured EIGRP correctly.

Q3. Is there any advantage I will get if I decide to run MHSRP or I am just making my network unnecessarily complex?

Yes (to 1st 1/2 of Q). Reduced router loading (no handling of packets unnecessarily) and higher performance (eliminate delay introduced by the extra Ethernet hop).

Yes (2 2nd 1/2 of Q). Assuming links are T1, you won't be able to measure the difference.

You're welcome :-)

Vincent C Jones

www.networkingunlimited.com

1 REPLY
Silver

Re: HSRP and EIGRP. Do I need MHSRP?

ANSWERS:

Q1. Should I define two HSRP groups so that my PIX gets two outside gateways and sends data destined for Site A to Ra and data for site B to Rb.

Yes. No reason not to and no reason to incur extra hops which are not needed.

Q2. If I only define one HSRP group, wont EIGRP anyways direct all traffic destined to SiteB to Rb?

Yes. Assuming you have configured EIGRP correctly.

Q3. Is there any advantage I will get if I decide to run MHSRP or I am just making my network unnecessarily complex?

Yes (to 1st 1/2 of Q). Reduced router loading (no handling of packets unnecessarily) and higher performance (eliminate delay introduced by the extra Ethernet hop).

Yes (2 2nd 1/2 of Q). Assuming links are T1, you won't be able to measure the difference.

You're welcome :-)

Vincent C Jones

www.networkingunlimited.com

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