Basic BGP question on 4507's and consideration for HSRP

Answered Question
Feb 24th, 2010
User Badges:

Hi, can you confirm this:


Imagine that on 4507's gw5 and gw6 I need to change from static route (advertising network 10.1.0.0) to BGP. I want to peer gw5 and gw6 with the 7206 router site1-br-gw. Please find attached config for both gw5 and gw6 and detailed diagram attached.


My question is this:
Given that the two 4507's gw5 and gw6 are configured with HSRP, what would be the impact on BGP configuation? I mean, do I need to configure a route-map to make one of the 4507 as preferred or just let BGP dynamically select that? If so, if you can give me a hint on how that configuration would look like that is appreciated.


This is the configuration that I came up with, but if I recall correctly I should specify via a route-map which 4507 will be the primary(?)


gw5

router bgp 100
neighbor 10.1.47.193 description site1-br-gw
neighbor 10.1.47.193 remote-as 65111
neighbor 10.1.255.16 description gw6

neighbor 10.1.255.16 remote-as 100
network  10.1.0.0 mask 255.255.0.0




gw6
router bgp 100
neighbor 10.1.47.193 description site1-br-gw
neighbor 10.1.47.193 remote-as 65111
neighbor 10.1.255.15 description gw5

neighbor 10.1.255.15 remote-as 100
network  10.1.0.0 mask 255.255.0.0

Correct Answer by Giuseppe Larosa about 7 years 3 months ago

Hello Marlon,

as soon as you remove the static route on C7206 for net 10.1.0.0 the presence of HSRP on the C4507 becomes meaningless, and the C7206 can use the BGP route thar it considers best (if all devices are in same BGP AS 100 the best path is that coming from device with lowest BGP router-id if all other parameters are the same).


if the HSRP group was used only by the C7206 you could even remove it, but if it is needed by the ASA you need to keep it and it will not have effects on routing with the C7206.


Hope to help

Giuseppe

  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 5 (1 ratings)
Loading.
Correct Answer
Giuseppe Larosa Wed, 02/24/2010 - 12:14
User Badges:
  • Super Silver, 17500 points or more
  • Hall of Fame,

    Founding Member

Hello Marlon,

as soon as you remove the static route on C7206 for net 10.1.0.0 the presence of HSRP on the C4507 becomes meaningless, and the C7206 can use the BGP route thar it considers best (if all devices are in same BGP AS 100 the best path is that coming from device with lowest BGP router-id if all other parameters are the same).


if the HSRP group was used only by the C7206 you could even remove it, but if it is needed by the ASA you need to keep it and it will not have effects on routing with the C7206.


Hope to help

Giuseppe

Actions

This Discussion