[FROG] how to get routing table entries with different src ip / from dummy interface?

Stefan Priebe - Profihost AG s.priebe at profihost.ag
Tue Sep 17 03:49:17 EDT 2019


Hi,

i've now also tried to put the IP 37.228.152.2/32 at lo AND dummy0 +
neighbor 37.228.152.2 update-source 37.228.152.3 but this still results in:
# show ip route 52.218.237.186
Routing entry for 52.218.237.0/24
  Known via "bgp", distance 200, metric 0, best
  Last update 00:01:18 ago
    37.228.152.2 (recursive)
  *   192.0.2.2, via br99

so the correct src of 37.228.152.3 is still missing in frr route entry.

Greets,
Stefan

Am 17.09.19 um 09:13 schrieb Stefan Priebe - Profihost AG:
> Hi Jan,
> 
> Am 17.09.19 um 09:00 schrieb Jan Marquardt:
>> Hi Stefan,
>>
>> as far as I remember I had a similar issue some time ago which
>> I solved by adding the addresses to lo instead of dummyN.
> 
> yes i saw your issue but was not able to solve mine with the notes in
> the bug report.
> 
> If i move my IP from dummy0 to lo i do not even get a successful bgp
> connection.
> 
> What i tried:
> 
> # ip a l dev lo
> 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN
> group default qlen 1
>     link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
>     inet 127.0.0.1/8 scope host lo
>        valid_lft forever preferred_lft forever
>     inet 37.228.152.3/32 scope global lo
>        valid_lft forever preferred_lft forever
>     inet6 fe80::200:ff:fe00:0/64 scope link
>        valid_lft forever preferred_lft forever
>     inet6 ::1/128 scope host
>        valid_lft forever preferred_lft forever
> 
> so ip is bound to lo.
> 
> frr.conf:
>  neighbor internal-bgp update-source 37.228.152.3
>  neighbor 37.228.152.2 peer-group internal-bgp
> 
> 
> but:
> # show ip bgp sum
> ...
> 37.228.152.2    4      34432       0       0        0    0    0    never
>      Connect
> ...
> 
> So it always stays just in connect mode and never connects.
> 
> This most probably happens because a connection is not possible from lo:
> # ping -I lo 37.228.152.2
> PING 37.228.152.2 (37.228.152.2) from 37.228.152.3 lo: 56(84) bytes of data.
> 
> The route to 37.228.152.2 is set up like this:
> # route -n | grep 37.228.152.2
> 37.228.152.2    192.0.2.2       255.255.255.255 UGH   20     0        0 br99
> 
> Stefan
> 
>>
>> Best Regards
>>
>> Jan
>>
>>> Am 17.09.2019 um 08:48 schrieb Stefan Priebe - Profihost AG <s.priebe at profihost.ag>:
>>>
>>> Hello list,
>>>
>>> i'm trying to get an linux kernel routing table entry like this one:
>>> # ip r get 52.218.237.186
>>> 52.218.237.186 via 192.0.2.2 dev br99 src 37.228.152.3
>>>
>>> but frr always creates entries like this one:
>>> # ip r get 52.218.237.186
>>> 52.218.237.186 via 192.0.2.2 dev br99 src 192.0.2.3
>>>
>>> 37.228.152.3 is an ip of an dummy0 interface and 192.0.2.3 is the ip of
>>> br99.
>>>
>>> frr.conf:
>>>
>>> router bgp XXXXX
>>> bgp router-id 37.228.152.3
>>> neighbor internal-bgp peer-group
>>> neighbor internal-bgp remote-as XXXXX
>>> neighbor internal-bgp capability dynamic
>>> neighbor 37.228.152.2 peer-group internal-bgp
>>> neighbor 37.228.152.2 description R2
>>> neighbor 37.228.152.2 update-source dummy0
>>> !
>>> address-family ipv4 unicast
>>>  neighbor 37.228.152.2 next-hop-self
>>> exit-address-family
>>> !
>>>
>>> Greets,
>>> Stefan
>>>
>>> _______________________________________________
>>> frog mailing list
>>> frog at lists.frrouting.org
>>> https://lists.frrouting.org/listinfo/frog
>>



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