topic BGP sessions not exporting in General Topics

BGP sessions not exporting

darren_g — Mon, 24 Jun 2019 02:00:35 GMT

Hi folks/

I'm trying to use BGP to synchronise routing across two ISPec tunnels to a Palo Alto HA cluster.

I have BGP connectivity established - the remote end is exporting the routes I want, and they're being seen (and managed correctly) by the Palo Alto as far as I can tell.

However, I can't seem to get the Palo Alto to export routes BACK to the other end. I don't want a default route - I just want selective routes from the Palo Alto end sent to the remote device for insertion into its routing table (this is to provide routing redundancy across the redundant tunnels into the PA).

Can anyons suggest where I could start to see WHY it's not exporting?

This is what I get from querying the PA

show routing protocol bgp loc-rib

VIRTUAL ROUTER: default (id 1)
==========
Prefix Nexthop Peer Weight LocPrf Org MED flap AS-Path
*192.168.220.0/24 169.254.55.10 Singtel-link1 0 100 i/c 0 0 64513
192.168.220.0/24 169.254.55.14 Singtel-link2 0 100 i/c 0 0 64513

total routes shown: 2

show routing protocol bgp rib-out

VIRTUAL ROUTER: default (id 1)
==========
Prefix Nexthop Peer Originator Adv Status Aggr Status AS-Path

total routes shown: 0

So I can see the routes coming IN - but nothing going out.

Yes, I have configured an export in the BGP profile - it's just not actually exporting.

Can anyone suggest where I could start looking to find out why this isn;t going?

Thanks

Re: BGP sessions not exporting

jeremy.larsen — Tue, 25 Jun 2019 17:19:27 GMT

A couple simple suggestions from my own troubleshooting.

I found there are a couple spots where "enable" isn't checked by default. Under the general BGP tab do you have "enable" checked at the top and "Install Route" checked as well? Under the "Peer Group" tab do you have your peer groups set the "Enable" as well? Are you using any kind or Redistribution profiles and are they set under "Redist Rules"? Is this iBGP or eBGP?

Re: BGP sessions not exporting

darren_g — Tue, 25 Jun 2019 22:21:50 GMT

@jeremy.larsen wrote:
A couple simple suggestions from my own troubleshooting.

I found there are a couple spots where "enable" isn't checked by default. Under the general BGP tab do you have "enable" checked at the top and "Install Route" checked as well? Under the "Peer Group" tab do you have your peer groups set the "Enable" as well? Are you using any kind or Redistribution profiles and are they set under "Redist Rules"? Is this iBGP or eBGP?

hi jeremy.

Thanks for the reply.

yes, the unticked boxes caught me out at first - but they're definitely both enabled, and "install route" is ticked as well - the route from the remote peer is installed, and is in the BGP local RIB

I now have a redistribution profile setup and installed - which I missed the first time around - and the routes I want are installed intot he BGP local RIB as well, vis-a-vis

show routing protocol bgp loc-rib

VIRTUAL ROUTER: default (id 1)
==========
Prefix Nexthop Peer Weight LocPrf Org MED flap AS-Path
*192.168.220.0/24 169.254.55.10 external-link1 0 100 i/c 0 0 64513
192.168.220.0/24 169.254.55.14 external-link2 0 100 i/c 0 0 64513
*172.20.2.0/23 172.20.200.2 Local 0 100 i/c 0 0
*172.20.12.0/24 172.20.200.2 Local 0 100 i/c 0 0
*172.20.13.0/24 172.20.200.2 Local 0 100 i/c 0 0

but the 172.x.x. routes are still not being exported to the remote peers.

This is eBGP. I'm using this to provide redudnant routing to a remote node over two IPSec tunnels.

I've logged a case with TAC to see if they can tell me where I'm being dumb.

Re: BGP sessions not exporting

jeremy.larsen — Wed, 26 Jun 2019 12:55:45 GMT

Are your 172.x.x.x routes "Connected" routes or are they aggregate routes you want to manually inject? I'm spinning up something similar in my lab. I'm trying to remember if they have to exist in the routing table (ie - via static route entry, etc) for them to actually push out via BGP. It looks to me like they do exist based on your copy/paste. I'll let you know what I run into. I do remember routing protocols over VPN being a bit tricky with PAN as there is a built in mechanism for route propogation, but it's been awhile since I've played with it.

Re: BGP sessions not exporting

darren_g — Wed, 26 Jun 2019 21:22:46 GMT

@jeremy.larsen wrote:
Are your 172.x.x.x routes "Connected" routes or are they aggregate routes you want to manually inject? I'm spinning up something similar in my lab. I'm trying to remember if they have to exist in the routing table (ie - via static route entry, etc) for them to actually push out via BGP. It looks to me like they do exist based on your copy/paste. I'll let you know what I run into. I do remember routing protocols over VPN being a bit tricky with PAN as there is a built in mechanism for route propogation, but it's been awhile since I've played with it.

The routes I want to advertise (172.x.x.x) are static routes, in the routing table.

They're also in the BGP local RIB now I've got a redistribution profile configured and attached properly.

What's got me beat is that the imported route from the remote peer works fine - it just won't export the routes I want. BGP is running - the peer is there, and it's doing its thing - it just isn't exporting.

Re: BGP sessions not exporting

jeremy.larsen — Wed, 26 Jun 2019 21:28:58 GMT

Are you missing the "Redist Rule" under BGP that uses the Redistribution Profile?

Re: BGP sessions not exporting

darren_g — Wed, 26 Jun 2019 21:34:58 GMT

@jeremy.larsen wrote:
Are you missing the "Redist Rule" under BGP that uses the Redistribution Profile?

Nope. I've got it set to redistribute statis routes, and am using the "export" filter to limit the routes I want to export to the other end.

All the routes I want to export are in the static routing table exactly as specified in the filter.

Re: BGP sessions not exporting

jeremy.larsen — Thu, 27 Jun 2019 12:44:25 GMT

I'm curious what's in your export filter. Also, have you tried not using the filter as well? You've got me scratching my head as well now.

Re: BGP sessions not exporting

darren_g — Thu, 27 Jun 2019 21:22:14 GMT

It's pretty simple

I just tried it with the export filter disabled - no difference

Re: BGP sessions not exporting

darren_g — Fri, 28 Jun 2019 05:14:52 GMT

@jeremy.larsen wrote:
I'm curious what's in your export filter. Also, have you tried not using the filter as well? You've got me scratching my head as well now.

OK, I tried again with just deleting the export filter - and stuff me, it started to work.

The redistribution profile is controlling what routes get advertised anyway, so I don't need the filter.

I don't know what was breaking it - but it's working now, and in the spirit of "If it 'aint broke, don't stuff with it", I'm leaving it the way it is.

Thanks for your input.

Re: BGP sessions not exporting

jeremy.larsen — Fri, 28 Jun 2019 19:59:03 GMT

I'm not super genius with BGP. I have learned the hard way that filters and aggregates don't always work the way you think. Is this filter smaller or larger than what is advertised without it?

Re: BGP sessions not exporting

darren_g — Mon, 01 Jul 2019 23:58:02 GMT

The filters were identical to the routes in the normal RIB, and exactly the same as what was in the redistribution rule.

Even the TAC guy doesn't know why. I don't really care - it's working, and that's all that matters.