[FROG] ibgp regression on 8.5.2 ?

Fri Jun 30 12:56:12 UTC 2023

Thanks, I added the same information (under Attention) here too:
https://github.com/FRRouting/frr/releases/tag/frr-8.5.2.

On Fri, Jun 30, 2023 at 3:53 PM mike tancsa <mike at sentex.net> wrote:

> OK, it might be worthwhile putting in the next release notes a heads up as
> I am guessing there will be others who will be hit by this.  I am a bit
> leary of the practice of having to upgrade everything together at once. It
> opens me up to other bugs being far more catastrophic globally vs isolated
> to the one router.
>
>     ---Mike
> On 6/30/2023 8:36 AM, Donatas Abraitis wrote:
>
> Unfortunately, this is horrible, but no. iBGP peers exchange AIGP
> attributes. Workaround would be to switch to using eBGP sessions
> temporarily if possible.
>
> On Fri, Jun 30, 2023 at 3:27 PM mike tancsa <mike at sentex.net> wrote:
>
>> Hi,
>>
>>     Thanks for the explanation.  Is there any way to work around this via
>> configuration ? e.g. temporarily ignore the setting as Transitive ? This
>> makes for upgrading very intrusive as I have to upgrade all the ibgp
>> routers at once which is very service effecting.
>>
>>     ---Mike
>> On 6/30/2023 3:20 AM, Donatas Abraitis wrote:
>>
>> Hello, Mike!
>>
>> With the 8.5.0 release, the new BGP attribute AIGP (Accumulated IGP
>> Metric Attribute) was introduced. This new attribute was mistakenly set as
>> Transitive. This was fixed (53afb27
>> <https://github.com/FRRouting/frr/commit/53afb27eb892a107c9426a01dbba82bee6fa86a7>)
>> with the 8.5.2 release, but it's not backward-compatible between 8.5.x
>> versions. We suggest using only the latest version of the 8.5 release.
>>
>> If you see such errors/notifications, upgrade to the latest 8.5.x
>> versions, and avoid using 8.5.0, and 8.5.1.
>>
>> AIGP attribute must be flagged as "Transitive"
>>
>> %NOTIFICATION: received from neighbor X.Y.Z.W 3/4 (UPDATE Message Error/Attribute
>> Flags Error) 14 bytes 80 1a 0b 01 00 0b 00 00 00 00 00 00 00 01
>>
>> (This affects only iBGP sessions).
>>
>> On Fri, Jun 30, 2023 at 12:09 AM mike tancsa <mike at sentex.net> wrote:
>>
>>> Hi, I am guessing it is this commit ?
>>>
>>> commit 231e4de73f46b9c75a07bf0144aafce18aeb3a55
>>> Author: Donatas Abraitis <donatas at opensourcerouting.org>
>>> Date:   Mon May 8 22:49:10 2023 +0300
>>>
>>>      bgpd: Make sure AIGP attribute is non-transitive
>>>
>>>      The AIGP attribute is an optional, non-transitive BGP path
>>> attribute.
>>>
>>>      Signed-off-by: Donatas Abraitis <donatas at opensourcerouting.org>
>>>
>>>
>>> Is there a way to work around this in configs ?
>>>
>>>      ---Mike
>>>
>>> On 6/29/2023 2:39 PM, mike tancsa wrote:
>>> > I was updating an internal distribution router that got wedged in
>>> > vtysh from 8.5 to 8.5.2 and found all my ibgp peers would not come up.
>>> > Same error on the half dozen peers
>>> >
>>> > Jun 29 14:00:55 ibgp-4 bgpd[38150]: [HZN6M-XRM1G] %NOTIFICATION:
>>> > received from neighbor xx.yy.zz.251 3/4 (UPDATE Message
>>> > Error/Attribute Flags Error) 14 bytes 80 1a 0b 01 00 0b 00 00 00 00 00
>>> > 00 00 01
>>> > Jun 29 14:01:00 ibgp-4 bgpd[38150]: [HZN6M-XRM1G] %NOTIFICATION:
>>> > received from neighbor xx.yy.zz.251 3/4 (UPDATE Message
>>> > Error/Attribute Flags Error) 14 bytes 80 1a 0b 01 00 0b 00 00 00 00 00
>>> > 00 00 01
>>> > Jun 29 14:01:05 ibgp-4 bgpd[38150]: [HZN6M-XRM1G] %NOTIFICATION: sent
>>> > to neighbor xx.yy.zz.251 3/4 (UPDATE Message Error/Attribute Flags
>>> > Error) 14 bytes c0 1a 0b 01 0
>>> >
>>> > On the older versions of frr,
>>> >
>>> > [NYD0B-A3BTB][EC 33554433] AIGP attribute must be flagged as
>>> "Transitive"
>>> > [HZN6M-XRM1G] %NOTIFICATION: sent to neighbor xx.yy.zz.241 3/4 (UPDATE
>>> > Message Error/Attribute Flags Error) 14 bytes 80 1a 0b 01 0
>>> > [GW152-RVASS][EC 33554455] bgp_process_packet: BGP UPDATE receipt
>>> > failed for peer: xx.yy.zz.241
>>> >
>>> > I downgraded from 8.5.2 to 8.5.1 and all was good. Also, another peer
>>> > thats still running 7.x was fine with it all.
>>> >
>>> >
>>> > Nothing special about the config. One of the untouched boxes running
>>> 8.5
>>> >
>>> >  neighbor THOTLAN peer-group
>>> >  neighbor THOTLAN remote-as 11647
>>> >  neighbor THOTLAN description Core1LanEx
>>> >  neighbor THOTLAN update-source [dot.251]
>>> >  neighbor .241 peer-group HOTLAN
>>> >  neighbor .241 description The box the flipped out
>>> >  neighbor .241 bfd
>>> >   neighbor THOTLAN activate
>>> >   neighbor THOTLAN next-hop-self
>>> >   neighbor THOTLAN weight 111
>>> >
>>> > The box I tried to upgrade from 8.5 to 8.5.2 that then went back to
>>> 8.5.1
>>> >
>>> >  neighbor THOTLAN peer-group
>>> >  neighbor THOTLAN remote-as 11647
>>> >  neighbor THOTLAN update-source [dot.241]
>>> >  neighbor THOTLAN timers 16 50
>>> >  neighbor .251 description One of the many other peers that didnt like
>>> me
>>> >  neighbor .251 bfd
>>> >   neighbor THOTLAN activate
>>> >   neighbor THOTLAN next-hop-self
>>> >   neighbor THOTLAN soft-reconfiguration inbound
>>> >   neighbor THOTLAN weight 109
>>> >
>>> >
>>> >     ---Mike
>>> >
>>> >
>>>
>>
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