07-30-2007 12:31 PM - edited 03-03-2019 06:06 PM
Is it possible to setup a BGP peer using the HSRP virtual address as neighbour and source IP ?
07-30-2007 12:46 PM
Hi,
Please check this document as a best practice of running HSRP with BGP to provide redundancy:
http://www.cisco.com/en/US/tech/tk365/technologies_configuration_example09186a0080093f2c.shtml
HTH,
Mohammed Mahmoud.
07-30-2007 12:47 PM
No. First of all IOS doesn't let you specify the IP address as an option in the update-source command and you would have to specify an interface with the update-source command. Moreover it's not practical to use HSRP address for BGP peering as address doesn't always belong to the same device.
HTH
Sundar
07-30-2007 12:52 PM
Thanks for the response - My reason for thinking about it is that I wish the BGP peer to only be established with the device that is actively holding the HRSP VIP !
07-30-2007 01:05 PM
While using HSRP address for peering isn't an option BGP offers a wide range of options for redundancy and load sharing. If you can provide more details about your topology and what's that you are trying to achieve we can probably assist you with the configuration.
HTH
Sundar
07-30-2007 01:40 PM
Thanks - I think I can sort it out though.
07-30-2007 12:52 PM
You are only allowed to source from an interface, not from a virtual address.
While you are allowed to configure the neighbor pointing to the HSRP address, the remote connection will be refused since it will be sending the packet from an invalid IP address.
07-30-2007 12:55 PM
This is where I got to - so was hoping for a work-around !
Thanks anyway, after looking into this for a while I didn't think it was possible but just wanted a second opinion.
07-30-2007 01:48 PM
two options come to mind;
create the same anycast loopback address on both possible bgp peers of the third peer, put both in to the IGP, and let the igp determine the best path to each...
or just fully mesh to the loopback address of the peers.
Joe
11-16-2013 07:00 PM
As Jbrunner007 has mentioned, the only way to peer with HSRP would be with an anycast loopback. Let's say you have 3 routers: R1, R2, and R3. Let's assume all of these are on the same subnet for this example. R1 and R2 will be the HSRP peers and R3 will be the router trying to peer with the HSRP address. (Just putting in the signicant portions for the sake of brevity)
R1
int lo0
ip add 1.1.1.1 255.255.255.255
int gi0/0
ip add 2.2.2.2 255.255.255.0
standby 0 ip 2.2.2.1
router bgp 1
neigh 2.2.2.4 update-source l0
R2
int lo0
ip add 1.1.1.1 255.255.255.255
int gi0/0
ip add 2.2.2.3 255.255.255.0
standby 0 ip 2.2.2.1
router bgp 1
neigh 2.2.2.4 update-source l0
R3
int gi0/0
ip add 2.2.2.4 255.255.255.0
router bgp 2
neigh 1.1.1.1 remote-as 1
ip route 1.1.1.1 255.255.255.255 2.2.2.1
In this case we used a static route to get to the anycast loopback, if they aren't on the same subnet you'd need to rely on an IGP and tune the metrics so that R2 had a worse metric from R3.
02-28-2018 03:12 AM
This works perfeckly, already implemented this one on my LAB
03-01-2018 03:20 AM
I'm afraid each time HSRP flaps the BGP session will go Down/Up also.
And you are never sure which router you are peering to.
So it really makes a better sense to configure BGP peering to both routers.
BR,
Milan
03-01-2018 03:52 AM
09-05-2018 02:12 PM
You would know which router BGP was peering to since it is the active router on interface 2.2.2.1 correct?
Only 1 router will be active at a time. Or am I missing something? I am trying to setup this scenario also. I do not have the luxury of a second ISP.
09-05-2018 02:24 PM
Hello,
If your goal is to forward traffic only to the active hsrp router you could create 2 BGP sessions, one on each router, and then set the next-hop as the HSRP vip using a route-map on the bgp neighbors.
HTH,
ADP
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