[dev] Fwd: Problems regarding BGP code 2, sub-code 7 when peering with Cisco IOS-XR Version 4.2.3 over IPv6

Christoffer Hansen netravnen at gmail.com
Thu Oct 19 06:34:05 EDT 2017


But yes.

All the fuzz is the fault of the Cisco IOS-XR platform not supporting
the add-path capability for eBGP peerings :/

> Add path is not be supported with MDT, tunnel, and L2VPN address families and eBGP peerings.
https://www.cisco.com/c/en/us/td/docs/routers/crs/software/crs_r4-2/routing/configuration/guide/b_routing_cg42crs/b_routing_cg42crs_chapter_01.html

Cisco has only implemented iBGP support for the add-path functionality
(do not know if they have done something different in IOS-XR 6.x releases)

Regards,
Christoffer.
gpg: c8b3 82a8 a1cd cdb7 71fe  b24c c654 948f da86 becd


-------- Forwarded Message --------
Subject: Re: [dev] Problems regarding BGP code 2, sub-code 7 when
peering with Cisco IOS-XR Version 4.2.3 over IPv6
Date: Tue, 17 Oct 2017 14:48:40 +0200
From: Christoffer Hansen <netravnen at gmail.com>
To: Daniel Walton <dwalton at cumulusnetworks.com>
CC: FRRouting-Dev <dev at lists.frrouting.org>

> Any chance you can get a .pcap of the session that is bouncing?

Refer to attached file. "my-packetcapture.cap"

----

Had the dreary experiencing today (again) when trying to setup a HE
(full feed) BGP tunnel between the pfSense FRR daemon and HE Frankfurt
BGP endpoint.

Refer to attached file. "henetv6-bgp-tunnel-packetcapture.cap"

----

Regards,
Christoffer.
gpg: c8b3 82a8 a1cd cdb7 71fe b24c c654 948f da86 becd
On 9/26/2017 20:19, Daniel Walton wrote:
> Hi Christoffer,
> FRR will always advertise the capability for "RX addpath" but we will
> only advertise "TX addpath" if you configure one of the "neighbor
> x.x.x.x addpath...." knobs.  In your case it sounds like XR is getting
> confused about us sending the "RX addpath" capability on a v6 session.
>  That shouldn't cause it to send a NOTIFICATION though so I am wondering
> if maybe we are formatting something incorrectly in the OPEN.  Any
> chance you can get a .pcap of the session that is bouncing?
>
> thx
> Daniel
>
>
> On Tue, Sep 26, 2017 at 12:06 PM, Christoffer Hansen
> <netravnen at gmail.com <mailto:netravnen at gmail.com>> wrote:
>
>     FRRouting-Dev <dev at lists.frrouting.org <mailto:dev at lists.frrouting.org>>
>
>
>     Hit an interesting issue today. (for reference a lot of technical
>     details below)
>
>     I found myself unable to locate the option of turning BGP code 2,
>     sub-code 7 off when sending capabilities to a neighbor. (Spent some time
>     googling around but mostly found Cisco IOS-XR related stuff)
>
>     It appears Cisco IOS-XR does not yet support the use off
>     'additional-paths' (BGP code 2, sub-code 7) when exchanging neighbor
>     capabilities. But ONLY for IPv6 (IPv4 is supported).
>
>     So my question to the list (if anyone finds the time to answer) is: Does
>     FFRouting contain an option to turn off the multi-path feature /
>     specific sub-code when announcing BGPv4 capabilities to it's neighbor(s)
>     over IPv6 (or both IPv4/v6) ?
>
>     Nb: And yes. Have tried disabling sending capabilities to the IOS-XR
>     router altogether. But the the Cisco router just refuses because no
>     capabilities is announced from neighbor.
>
>     Nb(2): Capability option is set to 'Dynamic' when announcing to
>     neighbor.
>
>     --
>     Regards,
>     Christoffer.
>     gpg: c8b3 82a8 a1cd cdb7 71fe  b24c c654 948f da86 becd
>
>
>     Software Details
>     ================
>
>     pfSense v2.3.4
>     --------------
>     * Name: frr
>     * Category: net
>     * Version: 0.0.2
>     * Description: FRR routing daemon for BGP, OSPF, and OSPF6 Conflicts
>     with Quagga OSPF and OpenBGPD. These packages cannot be installed at the
>     same time.
>
>
>     Debug output from Cisco IOS XR Software, Version 4.2.3[Default]
>     ===============================================================
>
>     * NOTE(1): IPv6 network prefix replaced with '2001:db8::'
>
>     RP/0/RSP0/CPU0:Sep 26 16:49:36.532 MEST: bgp[1048]: [default-ioct] VRF
>     Internet: 2001:db8:::250:56ff:febd:7e57 went from Idle to Connect
>     RP/0/RSP0/CPU0:Sep 26 16:49:36.754 MEST: bgp[1048]: [default-iord] VRF
>     Internet: Received message from 2001:db8:::250:56ff:febd:7e57 with type
>     1, length (incl. header) 102
>     RP/0/RSP0/CPU0:Sep 26 16:49:36.754 MEST: bgp[1048]: [default-iord] VRF
>     Internet: Receive message dump for 2001:db8:::250:56ff:febd:7e57:
>     RP/0/RSP0/CPU0:Sep 26 16:49:36.754 MEST: bgp[1048]: [default-iord] VRF
>     Internet: ffff ffff ffff ffff ffff ffff ffff ffff
>     RP/0/RSP0/CPU0:Sep 26 16:49:36.755 MEST: bgp[1048]: [default-iord] VRF
>     Internet: 0066 0104 ff4c 0078 5774 0604 4902 0601
>     RP/0/RSP0/CPU0:Sep 26 16:49:36.755 MEST: bgp[1048]: [default-iord] VRF
>     Internet: 0400 0100 0102 0280 0002 0202 0002 0641
>     RP/0/RSP0/CPU0:Sep 26 16:49:36.755 MEST: bgp[1048]: [default-iord] VRF
>     Internet: 0400 00ff 4c02 0645 0400 0101 0102 0242
>     RP/0/RSP0/CPU0:Sep 26 16:49:36.756 MEST: bgp[1048]: [default-iord] VRF
>     Internet: 0002 0243 0002 1949 1715 6677 3031 2e6c
>     RP/0/RSP0/CPU0:Sep 26 16:49:36.756 MEST: bgp[1048]: [default-iord] VRF
>     Internet: 6162 2e6e 6574 7261 766e 656e 2e65 7500
>     RP/0/RSP0/CPU0:Sep 26 16:49:36.756 MEST: bgp[1048]: [default-iord] VRF
>     Internet: 0204 4002 8078
>     RP/0/RSP0/CPU0:Sep 26 16:49:36.756 MEST: bgp[1048]: [default-iord] VRF
>     Internet: Received OPEN from 2001:db8:::250:56ff:febd:7e57, version 4,
>     holdtime 120 secs
>     RP/0/RSP0/CPU0:Sep 26 16:49:36.756 MEST: bgp[1048]: [default-iord] VRF
>     Internet: OPEN from 2001:db8:::250:56ff:febd:7e57 has optional parameter
>     type: 2 (Capability) len: 6
>     RP/0/RSP0/CPU0:Sep 26 16:49:36.756 MEST: bgp[1048]: [default-iord] VRF
>     Internet: OPEN from 2001:db8:::250:56ff:febd:7e57 has
>     MULTIPROTOCOL_EXTENSION capability for afi/safi: 1/1
>     RP/0/RSP0/CPU0:Sep 26 16:49:36.757 MEST: bgp[1048]: [default-iord] VRF
>     Internet: OPEN from 2001:db8:::250:56ff:febd:7e57 has optional parameter
>     type: 2 (Capability) len: 2
>     RP/0/RSP0/CPU0:Sep 26 16:49:36.757 MEST: bgp[1048]: [default-iord] VRF
>     Internet: OPEN from 2001:db8:::250:56ff:febd:7e57 has ROUTE-REFRESH
>     capability(old) for all address-families
>     RP/0/RSP0/CPU0:Sep 26 16:49:36.757 MEST: bgp[1048]: [default-iord] VRF
>     Internet: OPEN from 2001:db8:::250:56ff:febd:7e57 has optional parameter
>     type: 2 (Capability) len: 2
>     RP/0/RSP0/CPU0:Sep 26 16:49:36.757 MEST: bgp[1048]: [default-iord] VRF
>     Internet: OPEN from 2001:db8:::250:56ff:febd:7e57 has ROUTE-REFRESH
>     capability for all address-families
>     RP/0/RSP0/CPU0:Sep 26 16:49:36.757 MEST: bgp[1048]: [default-iord] VRF
>     Internet: OPEN from 2001:db8:::250:56ff:febd:7e57 has optional parameter
>     type: 2 (Capability) len: 6
>     RP/0/RSP0/CPU0:Sep 26 16:49:36.757 MEST: bgp[1048]: [default-iord] VRF
>     Internet: OPEN from 2001:db8:::250:56ff:febd:7e57 has 4-byte AS
>     capability with AS 65356
>     RP/0/RSP0/CPU0:Sep 26 16:49:36.758 MEST: bgp[1048]: [default-iord] VRF
>     Internet: OPEN from 2001:db8:::250:56ff:febd:7e57 has optional parameter
>     type: 2 (Capability) len: 6
>     RP/0/RSP0/CPU0:Sep 26 16:49:36.758 MEST: bgp[1048]: [default-iord] VRF
>     Internet: 2001:db8:::250:56ff:febd:7e57 Addr-family 1/1 not supported:
>     Ignoring the ADDPATH capability
>     RP/0/RSP0/CPU0:Sep 26 16:49:36.758 MEST: bgp[1048]: [default-iord] VRF
>     Internet: OPEN from 2001:db8:::250:56ff:febd:7e57 has optional parameter
>     type: 2 (Capability) len: 2
>     RP/0/RSP0/CPU0:Sep 26 16:49:36.758 MEST: bgp[1048]: [default-iord] VRF
>     Internet: OPEN from 2001:db8:::250:56ff:febd:7e57 has unrecognized
>     capability code: 66, length 0 (ignored)
>     RP/0/RSP0/CPU0:Sep 26 16:49:36.758 MEST: bgp[1048]: [default-iord] VRF
>     Internet: OPEN from 2001:db8:::250:56ff:febd:7e57 has optional parameter
>     type: 2 (Capability) len: 2
>     RP/0/RSP0/CPU0:Sep 26 16:49:36.759 MEST: bgp[1048]: [default-iord] VRF
>     Internet: OPEN from 2001:db8:::250:56ff:febd:7e57 has unrecognized
>     capability code: 67, length 0 (ignored)
>     RP/0/RSP0/CPU0:Sep 26 16:49:36.759 MEST: bgp[1048]: [default-iord] VRF
>     Internet: OPEN from 2001:db8:::250:56ff:febd:7e57 has optional parameter
>     type: 2 (Capability) len: 25
>     RP/0/RSP0/CPU0:Sep 26 16:49:36.759 MEST: bgp[1048]: [default-iord] VRF
>     Internet: OPEN from 2001:db8:::250:56ff:febd:7e57 has unrecognized
>     capability code: 73, length 23 (ignored)
>     RP/0/RSP0/CPU0:Sep 26 16:49:36.759 MEST: bgp[1048]: [default-iord] VRF
>     Internet: OPEN from 2001:db8:::250:56ff:febd:7e57 has optional parameter
>     type: 2 (Capability) len: 4
>     RP/0/RSP0/CPU0:Sep 26 16:49:36.759 MEST: bgp[1048]: [default-iord] VRF
>     Internet: bgp_io_read_schedule_updgrp: NO updgrp scheduled after Open
>     processing: nbr=2001:db8:::250:56ff:febd:7e57, nbrfl=0x08314080
>     RP/0/RSP0/CPU0:Sep 26 16:49:36.759 MEST: bgp[1048]: [default-iord] VRF
>     Internet: 2001:db8:::250:56ff:febd:7e57 went from Connect to OpenSent
>     RP/0/RSP0/CPU0:Sep 26 16:49:36.760 MEST: bgp[1048]: [default-iord] VRF
>     Internet: Sending OPEN to 2001:db8:::250:56ff:febd:7e57, version 4, my
>     as: 31027, holdtime 120 seconds
>     RP/0/RSP0/CPU0:Sep 26 16:49:36.760 MEST: bgp[1048]: [default-iord] VRF
>     Internet: OPEN from 2001:db8:::250:56ff:febd:7e57 has capabilities with
>     no supported address-family.
>     RP/0/RSP0/CPU0:Sep 26 16:49:36.760 MEST: bgp[1048]: [default-iord] VRF
>     Internet: Sending NOTIFICATION 2/7 (unsupported/disjoint capability) to
>     2001:db8:::250:56ff:febd:7e57 (0 bytes: )
>     RP/0/RSP0/CPU0:Sep 26 16:49:36.760 MEST: bgp[1048]: [default-iord] VRF
>     Internet: 2001:db8:::250:56ff:febd:7e57 went from OpenSent to Closing
>     RP/0/RSP0/CPU0:Sep 26 16:49:36.761 MEST: bgp[1048]: [default-ioct] VRF
>     Internet: 2001:db8:::250:56ff:febd:7e57 send message type 3, length
>     (incl. header) 21
>     RP/0/RSP0/CPU0:Sep 26 16:49:36.761 MEST: bgp[1048]: [default-ioct] VRF
>     Internet: Send message dump for 2001:db8:::250:56ff:febd:7e57:
>     RP/0/RSP0/CPU0:Sep 26 16:49:36.761 MEST: bgp[1048]: [default-ioct] VRF
>     Internet: ffff ffff ffff ffff ffff ffff ffff ffff
>     RP/0/RSP0/CPU0:Sep 26 16:49:36.761 MEST: bgp[1048]: [default-ioct] VRF
>     Internet: 0015 0302 07
>     RP/0/RSP0/CPU0:Sep 26 16:49:36.762 MEST: bgp[1048]: [default-event] VRF
>     Internet: 2001:db8:::250:56ff:febd:7e57 went from Closing to Idle
>     RP/0/RSP0/CPU0:Sep 26 16:49:36.762 MEST: bgp[1048]: [default-event] VRF
>     Internet: 2001:db8:::250:56ff:febd:7e57 reset due to BGP
>     Notification sent
>
>
>     Output from pfSense FRR routing daemon
>     ======================================
>
>     * NOTE(1): IPv6 network prefix replaced with '2001:db8::'
>     * NOTE(2): IPv4 next-hop replaced with TEST-NET-3 address 203.0.113.4
>
>     BGP neighbor is 2001:db8::1, remote AS #ISP-ASN#, local AS 65356,
>     external link
>       BGP version 4, remote router ID 0.0.0.0
>       BGP state = Idle
>       Last read 00:00:27, Last write 00:00:11
>       Hold time is 120, keepalive interval is 40 seconds
>       Message statistics:
>         Inq depth is 0
>         Outq depth is 0
>                              Sent       Rcvd
>         Opens:                  4          0
>         Notifications:          0          4
>         Updates:                0          0
>         Keepalives:             0          0
>         Route Refresh:          0          0
>         Capability:             0          0
>         Total:                  4          4
>       Minimum time between advertisement runs is 0 seconds
>       Update source is 2001:db8::250:56ff:febd:7e57
>
>      For address family: IPv4 Unicast
>       Not part of any update group
>       Community attribute sent to this neighbor(extended)
>       0 accepted prefixes
>
>       Connections established 0; dropped 0
>       Last reset 00:00:27, due to NOTIFICATION received (OPEN Message
>     Error/Unsupported Capability)
>     Local host: 2001:db8::250:56ff:febd:7e57, Local port: 57277
>     Foreign host: 2001:db8::1, Foreign port: 179
>     Nexthop: 203.0.113.4
>     Nexthop global: 2001:db8::250:56ff:febd:7e57
>     Nexthop local: fe80::250:56ff:febd:7e57
>     BGP connection: shared network
>     BGP Connect Retry Timer in Seconds: 120
>     Next start timer due in 5 seconds
>     Read thread: off  Write thread: off
>
>
>     _______________________________________________
>     dev mailing list
>     dev at lists.frrouting.org <mailto:dev at lists.frrouting.org>
>     https://lists.frrouting.org/listinfo/dev
>     <https://lists.frrouting.org/listinfo/dev>
>
>


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