OpenBGPD and eBGP nexthop

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OpenBGPD and eBGP nexthop

Per Engelbrecht
Hi All

[20051019 snap i386]

Last night I switched from our old BGP setup (fbsd/zebra) to our new
obsd/openbgpd.
All but a single eBGP session to one of our peers was established.
The eBGP peer switched between 'active' and 'connected' and I could ping
both nexthop IP and peer IP but still no candy. (bgpctl == great)
Getting 'established' to this peer normally takes from 4-6 min.
Finally rolled back to our old setup.

The NOC@carrier verified the IP part of my setup i.e. correct (new)
nexthop IP etc.
Below I've listed first the Zebra part on the neighbor and further down
the OpenBGPD part. If someone can spot a misconfiguration (I can't) then
please speak up. I'm in a tight spot / at a dead-end.

   Fictive info:
   99999 is our AS
   yyy.yyy.yyy.0 is the network that I announce
   yyy.yyy.yyy.1 is our router id

   66666 is the remote-as
   aaa.aaa.aaa.163 is the local IP [on em0] facing the neithbor/peer
   aaa.aaa.aaa.161 is the new nexthop IP to the neithbor/peer
   xxx.xxx.xxx.99 is the neithbor/peer IP


<snip from zebra.conf>
...
router bgp 99999
no synchronization
bgp log-neighbor-changes
network yyy.yyy.yyy.0 mask 255.255.192.0
redistribute static
neighbor xxx.xxx.xxx.99 remote-as 66666
neighbor xxx.xxx.xxx.99 description eBGP
neighbor xxx.xxx.xxx.99 ebgp-multihop 10
neighbor xxx.xxx.xxx.99 send-community both
neighbor xxx.xxx.xxx.99 route-map BGPIN in
neighbor xxx.xxx.xxx.99 route-map BGPOUT out
(route-maps etc. left out)
...
</snip from zebra.conf>




<snip from bgpd.conf>
...
#macros
peer0="xxx.xxx.xxx.99"

#global conf
AS 99999
router-id yyy.yyy.yyy.1
listen on aaa.aaa.aaa.163
fib-update yes
log updates
network yyy.yyy.yyy.0/18 set localpref 200

#neighbors and peers
neighbor $peer0 {
    remote-as 66666
    descr eBGP
    local-address aaa.aaa.aaa.163
    set nexthop aaa.aaa.aaa.161
    multihop 10
    set localpref 100
    set weight 45
    announce self
}

#filter
(Other that adding a few BOGON net from
http://www.cymru.com/BGP/robbgp-bogon.html [double checked with IANA]
then the original filter section is untouched)


Any help is highly appreciated.

/per
[hidden email]

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Re: OpenBGPD and eBGP nexthop

Henning Brauer
* per engelbrecht <[hidden email]> [2005-11-07 19:01]:

> #neighbors and peers
> neighbor $peer0 {
>    remote-as 66666
>    descr eBGP
>    local-address aaa.aaa.aaa.163
>    set nexthop aaa.aaa.aaa.161
>    multihop 10
>    set localpref 100
>    set weight 45
>    announce self
> }

i highly doubt you want to manually set the nexthop.

aside from that, we'll need logs and a tcpdump to see why the session
does not get established.

--
BS Web Services, http://www.bsws.de/
OpenBSD-based Webhosting, Mail Services, Managed Servers, ...
Unix is very simple, but it takes a genius to understand the simplicity.
(Dennis Ritchie)

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Re: OpenBGPD and eBGP nexthop

Per Engelbrecht
Henning Brauer wrote:

> * per engelbrecht <[hidden email]> [2005-11-07 19:01]:
>
>>#neighbors and peers
>>neighbor $peer0 {
>>   remote-as 66666
>>   descr eBGP
>>   local-address aaa.aaa.aaa.163
>>   set nexthop aaa.aaa.aaa.161
>>   multihop 10
>>   set localpref 100
>>   set weight 45
>>   announce self
>>}
>
>
> i highly doubt you want to manually set the nexthop.

Hhhmm .. why not ?

>
> aside from that, we'll need logs and a tcpdump to see why the session
> does not get established.

Next run will be in upcomming weekend. I'll gather and pile anything.

Appreciate your input Henning.

/per
[hidden email]