04-02-2014 01:21 AM - edited 03-07-2019 06:57 PM
Hi.
There is two switches in the equation:
WS-C2960-24TT-L 12.2(55)SE5 C2960-LANBASEK9-M
and stack of
Switch Ports Model SW Version SW Image
------ ----- ----- ---------- ----------
1 12 WS-C3750G-12S 12.2(55)SE8 C3750-IPSERVICESK9-M
2 12 WS-C3750G-12S 12.2(55)SE8 C3750-IPSERVICESK9-M
* 3 24 WS-C3750G-24T 12.2(55)SE8 C3750-IPSERVICESK9-M
3 is a master
There is VTP domain with pruning off and RSPAN VLAN 1001
core#sho vlan remote-span
Remote SPAN VLANs
------------------------------------------------------------------------------
1001
there is RSPAN session on first:
#sho monitor session 1
Session 1
---------
Type : Remote Source Session
Source Ports :
Both : Fa0/11
Dest RSPAN VLAN : 1001
Port Fa0/11 is in access mode, VLAN 303
and on second:
core#sho monitor session 1
Session 1
---------
Type : Remote Destination Session
Source RSPAN VLAN : 1001
Destination Ports : Gi3/0/2
Encapsulation : Native
Ingress : Disabled
Problem is that i can't see any IPv6 multicast traffic (like ICMPv6 RA or such) on Gi3/0/2 which is absolutely sure there, because if i remove monitoring session on core switch and put Gi3/0/2 into trunk mode, i can see packets i need in vlan 1001:
# tcpdump -s0 -nnvei eth1 vlan 1001 and ip6
tcpdump: WARNING: eth1: no IPv4 address assigned
tcpdump: listening on eth1, link-type EN10MB (Ethernet), capture size 65535 bytes
14:17:37.059045 50:57:a8:f0:72:1b > 33:33:ff:00:00:01, ethertype 802.1Q (0x8100), length 90: vlan 1001, p 0, ethertype IPv6, (class 0xe0, hlim 255, next-header ICMPv6 (58) payload length: 32) 2abc:abc:1:600b::2 > ff02::1:ff00:1: [icmp6 sum ok] ICMP6, neighbor solicitation, length 32, who has 2abc:abc:1:600b::1
source link-address option (1), length 8 (1): 50:57:a8:f0:72:1b
14:17:38.083266 50:57:a8:f0:72:1b > 33:33:ff:00:00:01, ethertype 802.1Q (0x8100), length 90: vlan 1001, p 0, ethertype IPv6, (class 0xe0, hlim 255, next-header ICMPv6 (58) payload length: 32) 2abc:abc:1:600b::2 > ff02::1:ff00:1: [icmp6 sum ok] ICMP6, neighbor solicitation, length 32, who has 2abc:abc:1:600b::1
source link-address option (1), length 8 (1): 50:57:a8:f0:72:1b
14:17:39.107068 50:57:a8:f0:72:1b > 33:33:ff:00:00:01, ethertype 802.1Q (0x8100), length 90: vlan 1001, p 0, ethertype IPv6, (class 0xe0, hlim 255, next-header ICMPv6 (58) payload length: 32) 2abc:abc:1:600b::2 > ff02::1:ff00:1: [icmp6 sum ok] ICMP6, neighbor solicitation, length 32, who has 2abc:abc:1:600b::1
source link-address option (1), length 8 (1): 50:57:a8:f0:72:1b
There is no such problem with usual unicast and broadcast traffic.
Any suggestions?
04-02-2014 03:55 AM
Interestingly, i've found bug CSCsr64007 which i stubmbled upon on one of my switches during troubleshooting. The effect of this bug was that RSPAN took IPv6 multicast packets from unrelated VLANs and forwarded them into monitor port.
Looks like they have "fixed" it filtering IPv6 multicast completely.
Discover and save your favorite ideas. Come back to expert answers, step-by-step guides, recent topics, and more.
New here? Get started with these tips. How to use Community New member guide