Cannot make iBGP peering over IPv6 across two Extreme X770 switches running 21.1.2.14

[Sumanta_Ghosh]

Hi Experts

I can't make an IPv6 iBGP peering up across Extreme switches, connected back to back. IPv4 peering is working fine. It appears Extreme has some recurring issues with IPv6 configuration.

I tried turning on and off BFD options, still it doesn't work. The BGP state is stuck in Active and there is no TCP connection coming up with ports (Remote Port/Local Port). Can anyone suggest if this is an OS bug or some other issue? BGP nei details below. Ping works fine across the switches.

Peer Description :
IBGP Peer : fe80::204:96ff:fe99:75b0 AS : 65139
Enabled : Yes OperStatus : Up
Weight : 1 Shutdown-Priority : 1024
ConnectRetry : 120 MinAsOrig : 5
HoldTimeCfg : 180 KeepaliveCfg : 60
Source Interface : Not configured RRClient : No
EBGP-Multihop : No Remove Private AS : No
BFD : Off BFD Status : Not Required
Capabilities Config : 4-Byte-As,route-refresh (old & new),ipv6-unicast
Policy for NLRI Type ipv4-unicast
In Policy : None
Out Policy : None
NextHopSelf : Disabled Send Communities : No
Soft Input Recfg : Disabled Allow Looped AS-Path: No
Policy for NLRI Type ipv4-multicast
In Policy : None
Out Policy : None
NextHopSelf : Disabled Send Communities : No
Soft Input Recfg : Disabled Allow Looped AS-Path: No
Policy for NLRI Type ipv6-unicast
In Policy : None
Out Policy : None
NextHopSelf : Disabled Send Communities : No
Soft Input Recfg : Disabled Allow Looped AS-Path: No
Policy for NLRI Type ipv6-multicast
In Policy : None
Out Policy : None
NextHopSelf : Disabled Send Communities : No
Soft Input Recfg : Disabled Allow Looped AS-Path: No
State : ACTIVE
FSM Down since : Thu Dec 1 01:56:32 2016
(Duration: 0:0:00:00)
Remote Addr : fe80::204:96ff:fe99:75b0 Local Addr : ::
Remote Port : 0 Local Port : 0
Remote RouterId : 0.0.0.0 Local RouterId : 10.174.61.90
HoldTimeNegotiated : 0 KeepAliveNegotiated : 0
FsmTransitions : 0
InUpdateElapsedTime : 00:00:12:32 InMsgElapsedTime : 0:0:12:32
InUpdates : 0 OutUpdates (in TxQ) : 0 (0)
InTotalMsgs : 0 OutTotalMsgs : 0
InRouteRefreshes : 0 OutRouteRefreshes : 0
Capabilities Tx : None
Capabilities Rx : None
NLRI for the session: None
Last State : CONNECT Last Event : TCP_CLOSED
LastError : 'None'

BGP Peer Statistics
Total Peers : 8
EBGP Peers : 2 IBGP Peers : 6
RR Client : 0 EBGP Multihop : 0
Enabled : 8 Disabled : 0

[Sumanta_Ghosh]

Hello All

Thanks for your responses. It got fixed by changing the interface IPv6 address to the below:-

"fc00::/127"

[Erik_Auerswald]

Since link-local addresses (LLA) are only valid on one specific link, the interface where to use an LLA needs to specified explicitly.

[Baskar]

Hi Sumanta,

I think I got the issue in your configuration you must specify the
link-local address in the following format , I have shared the sample Configuration below please have a look.

Sw2
===

configure bgp AS-number 1
configure bgp routerid 2.2.2.2
create bgp neighbor fe80::204:96ff:fe99:c8c2%vlan1 remote-AS-number 1
enable bgp neighbor fe80::204:96ff:fe99:c8c2%vlan1
disable bgp neighbor fe80::204:96ff:fe99:c8c2%vlan1 capability ipv4-unicast
disable bgp neighbor fe80::204:96ff:fe99:c8c2%vlan1 capability ipv4-multicast
enable bgp neighbor fe80::204:96ff:fe99:c8c2%vlan1 capability ipv6-unicast
enable bgp

Sw1:
===

configure bgp AS-number 1
configure bgp routerid 1.1.1.1
create bgp neighbor fe80::204:96ff:fe99:e089%vlan1 remote-AS-number 1
enable bgp neighbor fe80::204:96ff:fe99:e089%vlan1
disable bgp neighbor fe80::204:96ff:fe99:e089%vlan1 capability ipv4-unicast
disable bgp neighbor fe80::204:96ff:fe99:e089%vlan1 capability ipv4-multicast
enable bgp neighbor fe80::204:96ff:fe99:e089%vlan1 capability ipv6-unicast
enable bgp

By execute the command "show ipconfig ipv6 " you get the IPv6 prefix for the link-local address.

sh ipconfig ipv6

Route Sharing : Disabled
Route Compression : Enabled
ICMP Redirect for Fast Path : Disabled
Max Shared Gateways : Current: 4 Configured: 4
Route Sharing Hash : CRC Lower
Ping Protection : Enabled for static routes Interval: 2 Misses: 3

Interface IPv6 Prefix Flags

vlan1 fe80::204:96ff:fe99:e089%vlan1/64 -EUfP--R-

Flags : D - Duplicate address detected on VLAN, T - Tentative address
E - Interface enabled, U - Interface up, f - IPv6 forwarding enabled,
i - Accept received router advertisements enabled,
R - Send redirects enabled, r - Accept redirects enabled
P - Prefix address

sh bgp neighbor

Peer AS Weight State InMsgs OutMsgs(InQ) Up/Down
-----------------------------------------------------------------------------------
Ie-- fe80::204:96ff:fe99:c8c2%vlan1 1 1 ESTABLISHED 12 13 (0 ) 0:0:07:04

Flags: (d) disabled, (e) enabled, (E) external peer, (I) internal peer
(m) EBGP multihop, (r) route reflector client

please let me know if you have any question or concern

[Baskar]

Hi Sumanta,

By using the link local address, i am able to connect the BGP peer, please have a look and please share the full BGP configuration. so i can help on that

* X450G2-48t-10G4.17 # sh bgp neighbor
Peer AS Weight State InMsgs OutMsgs(InQ) Up/Down
-----------------------------------------------------------------------------------
Ie-- fe80::204:96ff:fe99:e089%vlan1 1 1 ESTABLISHED 2 2 (0 ) 0:0:00:02