Hi all, I was performing a home lab and decided to test a new scenario including iBGP between a router and RS. That's a brief scheme of the lab: ### 5.5.5.1 5.5.5.2 6.6.6.100/24 6.6.6.6/24 6.6.6.101/24 Router3 (as3)---eBGP---> Router2 (as2)---iBGP/not a rs_client---> RS (as2)---eBGP / rs_client--- > Router1 (as1) 3.3.3.0/24 2.2.2.0/24 1.1.1.0/24 ### Since, as route 3.3.3.0/24 is seen in RS directly attached ( first asn is as3) with next-hop 6.6.6.100 (I've set the next-hop manually into the RS's config in bgp_in) I expect that Router1 should see it in the same way - with hext-hop 6.6.6.100. But the route is shown with next-hop 6.6.6.6 instead. The first asn is as3 as expected. Do you have any idea why the next-hop is not propagated from RS to R1 as present in the master table but changed to the local IP address ? I think its related with the "not a rs_client" relation between Router2 and RS. Any idea how this behavior may be changed ? Thank you in advance! -- --- *Dean Belev*
Am 17.08.12 07:38, schrieb Dean Belev (Neterra NMT):
Hi all,
I was performing a home lab and decided to test a new scenario including iBGP between a router and RS. That's a brief scheme of the lab:
### 5.5.5.1 5.5.5.2 6.6.6.100/24 6.6.6.6/24 6.6.6.101/24 Router3 (as3)---eBGP---> Router2 (as2)---iBGP/not a rs_client---> RS (as2)---eBGP / rs_client--- > Router1 (as1) 3.3.3.0/24 2.2.2.0/24
1.1.1.0/24 ###
Since, as route 3.3.3.0/24 is seen in RS directly attached ( first asn is as3) with next-hop 6.6.6.100 (I've set the next-hop manually into the RS's config in bgp_in) I expect that Router1 should see it in the same way - with hext-hop 6.6.6.100. But the route is shown with next-hop 6.6.6.6 instead. The first asn is as3 as expected.
Do you have any idea why the next-hop is not propagated from RS to R1 as present in the master table but changed to the local IP address ? I think its related with the "not a rs_client" relation between Router2 and RS. Any idea how this behavior may be changed ?
It's always a good idea to provide the corresponding config. Anyway, I guess "gateway direct" in the bgp protocol definition on RS for Router2 should do the trick. Rgds, Stefan
On Fri, Aug 17, 2012 at 08:38:42AM +0300, Dean Belev (Neterra NMT) wrote:
Hi all,
I was performing a home lab and decided to test a new scenario including iBGP between a router and RS. That's a brief scheme of the lab:
### 5.5.5.1 5.5.5.2 6.6.6.100/24 6.6.6.6/24 6.6.6.101/24 Router3 (as3)---eBGP---> Router2 (as2)---iBGP/not a rs_client---> RS (as2)---eBGP / rs_client--- > Router1 (as1) 3.3.3.0/24 2.2.2.0/24
1.1.1.0/24 ###
Since, as route 3.3.3.0/24 is seen in RS directly attached ( first asn is as3) with next-hop 6.6.6.100 (I've set the next-hop manually into the RS's config in bgp_in) I expect that Router1 should see it in the same way - with hext-hop 6.6.6.100.
The question is whether you set manually real next-hop or bgp_next_hop attribute. For BGP route propagation, bgp_next_hop attribute is more important. You should check route attributes by 'show route 3.3.3.0/24 all' on RS and R1. -- Elen sila lumenn' omentielvo Ondrej 'SanTiago' Zajicek (email: santiago@crfreenet.org) OpenPGP encrypted e-mails preferred (KeyID 0x11DEADC3, wwwkeys.pgp.net) "To err is human -- to blame it on a computer is even more so."
Stefan, Thank you. Now it works. Ondrej, Either setting it up in R1 (neighbor 6.6.6.6 next-hop-self) or in RS (if net ~ 3.3.3.0/24 then bgp_next_hop = 6.6.6.100) I see that in the RS's routing table the route takes the appropriate NEXT-HOP (BGP.next.hop: 6.6.6.100). But when I check it on Router1 - the route points to 6.6.6.6. Best~ --- *Dean Belev* Product Manager Neterra Ltd. Telephone: +359 2 975 16 16 Fax: +359 2 975 34 36 Mobile: +359 886 663 123 www.neterra.net <http://www.neterra.net> On 17.8.2012 ?. 13:45 ?., Ondrej Zajicek wrote:
On Fri, Aug 17, 2012 at 08:38:42AM +0300, Dean Belev (Neterra NMT) wrote:
Hi all,
I was performing a home lab and decided to test a new scenario including iBGP between a router and RS. That's a brief scheme of the lab:
### 5.5.5.1 5.5.5.2 6.6.6.100/24 6.6.6.6/24 6.6.6.101/24 Router3 (as3)---eBGP---> Router2 (as2)---iBGP/not a rs_client---> RS (as2)---eBGP / rs_client--- > Router1 (as1) 3.3.3.0/24 2.2.2.0/24
1.1.1.0/24 ###
Since, as route 3.3.3.0/24 is seen in RS directly attached ( first asn is as3) with next-hop 6.6.6.100 (I've set the next-hop manually into the RS's config in bgp_in) I expect that Router1 should see it in the same way - with hext-hop 6.6.6.100.
The question is whether you set manually real next-hop or bgp_next_hop attribute. For BGP route propagation, bgp_next_hop attribute is more important. You should check route attributes by 'show route 3.3.3.0/24 all' on RS and R1.
Sorry, There is a mistake bellow. Please read the following "Either setting it up in R1..." as "Either setting it up in R2..." Best~ --- *Dean Belev* Product Manager Neterra Ltd. Telephone: +359 2 975 16 16 Fax: +359 2 975 34 36 Mobile: +359 886 663 123 www.neterra.net <http://www.neterra.net> On 17.8.2012 ?. 14:10 ?., Dean Belev wrote:
Stefan,
Thank you. Now it works.
Ondrej,
Either setting it up in R1 (neighbor 6.6.6.6 next-hop-self) or in RS (if net ~ 3.3.3.0/24 then bgp_next_hop = 6.6.6.100) I see that in the RS's routing table the route takes the appropriate NEXT-HOP (BGP.next.hop: 6.6.6.100). But when I check it on Router1 - the route points to 6.6.6.6.
Best~
--- *Dean Belev* Product Manager
Neterra Ltd. Telephone: +359 2 975 16 16 Fax: +359 2 975 34 36 Mobile: +359 886 663 123 www.neterra.net <http://www.neterra.net> On 17.8.2012 ?. 13:45 ?., Ondrej Zajicek wrote:
On Fri, Aug 17, 2012 at 08:38:42AM +0300, Dean Belev (Neterra NMT) wrote:
Hi all,
I was performing a home lab and decided to test a new scenario including iBGP between a router and RS. That's a brief scheme of the lab:
### 5.5.5.1 5.5.5.2 6.6.6.100/24 6.6.6.6/24 6.6.6.101/24 Router3 (as3)---eBGP---> Router2 (as2)---iBGP/not a rs_client---> RS (as2)---eBGP / rs_client--- > Router1 (as1) 3.3.3.0/24 2.2.2.0/24
1.1.1.0/24 ###
Since, as route 3.3.3.0/24 is seen in RS directly attached ( first asn is as3) with next-hop 6.6.6.100 (I've set the next-hop manually into the RS's config in bgp_in) I expect that Router1 should see it in the same way - with hext-hop 6.6.6.100.
The question is whether you set manually real next-hop or bgp_next_hop attribute. For BGP route propagation, bgp_next_hop attribute is more important. You should check route attributes by 'show route 3.3.3.0/24 all' on RS and R1.
participants (4)
-
Dean Belev -
Dean Belev (Neterra NMT)
-
Ondrej Zajicek -
Stefan Jakob