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vlan tagging issue with VPC http://forum.gns3.net/topic12494.html |
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Author: | tasdevil [ Thu Oct 16, 2014 9:08 pm ] | ||||
Post subject: | vlan tagging issue with VPC | ||||
I am trying to lab up a scenario to demonstrate to me arp/cam table timing issues (e.g. http://www.ciscozine.com/unicast-floodi ... c-routing/), requiring asymmetric routing. topology attached. I have placed wireshark on the trunk link between the switches. When S2 pings FTP-Client, both ping requests and replies are tagged VLAN100. When FTP-Client pings S2, both ping requests and replies are tagged VLAN200. When S2 pings microcore linux 21, expected behaviour, ping requests are tagged VLAN100, replies are tagged VLAN200. When micocore linux 21 pings S2, both ping requests and replies are tagged VLAN200. When microcore Linux 22 pings Microcore Linux 21, expected behavirour, ping requests VLAN100, replies VLAN200. When micocore Linux 21 pings Microcore Linux 22, expected behaviour, ping requests VLAN200, replies VLAN100. So the VLANs are only being incorrectly tagged where the target is a VPC. I dont understand why this would be so. GNS3 1.0beta latest public release. Linux. c3745-adventerprisek9-mz.124-15.T14 ============================================================= FTP-Cl> sh NAME IP/MASK GATEWAY MAC LPORT RHOST:PORT FTP-Cl 10.0.0.100/24 10.0.0.1 00:50:79:66:68:01 20001 127.0.0.1:10001 fe80::250:79ff:fe66:6801/64 ============================================================= S2> sh NAME IP/MASK GATEWAY MAC LPORT RHOST:PORT S2 192.168.0.200/24 192.168.0.1 00:50:79:66:68:02 20003 127.0.0.1:10004 fe80::250:79ff:fe66:6802/64 S2> ============================================================= Ciscozine-1#sh int trunk Port Mode Encapsulation Status Native vlan Fa1/10 on 802.1q trunking 1 Port Vlans allowed on trunk Fa1/10 1-4094 Port Vlans allowed and active in management domain Fa1/10 1,100,200 Port Vlans in spanning tree forwarding state and not pruned Fa1/10 1,100,200 Ciscozine-1#sh vlan-s VLAN Name Status Ports ---- -------------------------------- --------- ------------------------------- 1 default active Fa1/3, Fa1/4, Fa1/5, Fa1/6 Fa1/7, Fa1/8, Fa1/9, Fa1/11 Fa1/12, Fa1/13, Fa1/14, Fa1/15 100 VLAN0100 active Fa1/0, Fa1/2 200 VLAN0200 active Fa1/1 Ciscozine-1#sh ip int br | e un Interface IP-Address OK? Method Status Protocol Vlan100 10.0.0.1 YES manual up up Vlan200 192.168.0.2 YES manual up up ============================================================= Ciscozine-2#sh int trunk Port Mode Encapsulation Status Native vlan Fa1/10 on 802.1q trunking 1 Port Vlans allowed on trunk Fa1/10 1-4094 Port Vlans allowed and active in management domain Fa1/10 1,100,200 Port Vlans in spanning tree forwarding state and not pruned Fa1/10 1,100,200 Ciscozine-2#sh vlan-s VLAN Name Status Ports ---- -------------------------------- --------- ------------------------------- 1 default active Fa1/3, Fa1/4, Fa1/5, Fa1/6 Fa1/7, Fa1/8, Fa1/9, Fa1/11 Fa1/12, Fa1/13, Fa1/14, Fa1/15 100 VLAN0100 active 200 VLAN0200 active Fa1/0, Fa1/1, Fa1/2 Ciscozine-2#sh ip int br | e un Interface IP-Address OK? Method Status Protocol Vlan100 10.0.0.2 YES manual up up Vlan200 192.168.0.1 YES manual up up
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Author: | rednectar [ Thu Oct 16, 2014 9:29 pm ] |
Post subject: | Re: vlan tagging issue with VPC |
Quote: topology attached. Found config files attached, but not your .gns3 topology Haven't read this thoroughly, but confirm that this is your problem: Quote: I have placed wireshark on the trunk link between the switches. When S2 pings FTP-Client, both ping requests and replies are tagged VLAN100. When FTP-Client pings S2, both ping requests and replies are tagged VLAN200. Whereas you would EXPECT to see When S2 pings FTP-Client, ping requests are tagged VLAN100; ping replies are tagged VLAN200 When FTP-Client pings S2, ping requests are tagged VLAN200; ping replies are tagged VLAN100 So the problem seems to lie with the Cisco Switches. And I note that you are using c3745-adventerprisek9-mz.124-15.T14 - which I KNOW has problems doing NAT - it may have other problems as well. So can I suggest you try a different IOS? |
Author: | rednectar [ Thu Oct 16, 2014 10:18 pm ] |
Post subject: | Re: vlan tagging issue with VPC |
Forget my previous reply Its a bug with VPCS When VPCS gets the ping request, for some reason it is NOT "routing" the reply, but simply sending the reply to the MAC address that sent the ping!! It SHOULD of course be sending it to the MAC of its default gateway. I'll report it to Paul Meng |
Author: | tasdevil [ Fri Oct 17, 2014 10:03 am ] |
Post subject: | Re: vlan tagging issue with VPC |
Thanks mate. :) Good catch, I missed noticing that. |
Author: | rednectar [ Sat Oct 18, 2014 12:16 am ] |
Post subject: | Re: vlan tagging issue with VPC |
Here's what I reported: Quote: Can you take a look at topic12494.html
This shows a problem with VPCS In the scenario, there are two VPCS and L3 switches (and some other stuff that doesn't matter). FTP-Client(VPC)----[v100]Ciscozine-1(L3 Sw)----[trunk]---Ciscozine-2(L3 Sw)[v200]---S2(VPC) FTP-Client pings S2. Here is what happens FTP-Client ARPs for default GW. Ciscozine-1 replies FTP-Client sends ping to Ciscozine-1's MAC Ciscozine-1 routes the ping to VLAN 200 - sends it to S2's MAC S2 gets the ping packet HERE IS THE PROBLEM S2 sends a ping reply to Ciscozine-1's MAC address WHAT SHOULD HAPPEN S2 sends an ARP for its default GW. Cisxozine-2 replies S2 sends the ping reply to Ciscozine-2's MAC address |
Author: | mirnshi [ Sun Oct 19, 2014 2:25 pm ] | ||
Post subject: | Re: vlan tagging issue with VPC | ||
It's a bug. Now it's fixed. Code: VPCS[6]> relay dump on dump on VPCS[6]> set dump detail mac dump flags: mac detail VPCS[6]> p 10.0.0.100 -1 -c 1 00:50:79:66:68:05 -> ff:ff:ff:ff:ff:ff ARP, OpCode: 1 (Request) Ether Address: 00:50:79:66:68:05 -> Broadcast Who has 192.168.0.1? Tell 192.168.0.200 cc:02:0b:c4:00:00 -> 00:50:79:66:68:05 ARP, OpCode: 2 (Reply) Ether Address: cc:02:0b:c4:00:00 -> 00:50:79:66:68:05 192.168.0.1 is at cc:02:0b:c4:00:00 00:50:79:66:68:05 -> cc:02:0b:c4:00:00 IPv4, id: a56f, length: 84, ttl: 64, sum: 0966 Address: 192.168.0.200 -> 10.0.0.100 Proto: icmp, type: 8, code: 0 Desc: Echo 10.0.0.100 icmp_seq=1 timeout VPCS[6]> cc:02:0b:c4:00:00 -> 00:50:79:66:68:05 IPv4, id: a56f, length: 84, ttl: 63, sum: 0a66 Address: 10.0.0.100 -> 192.168.0.200 Proto: icmp, type: 0, code: 0 Desc: Echo reply VPCS[6]> p 10.0.0.100 -1 -c 1 00:50:79:66:68:05 -> cc:02:0b:c4:00:00 IPv4, id: a575, length: 84, ttl: 64, sum: 0960 Address: 192.168.0.200 -> 10.0.0.100 Proto: icmp, type: 8, code: 0 Desc: Echo cc:01:0b:c2:00:00 -> 00:50:79:66:68:05 IPv4, id: a56f, length: 84, ttl: 63, sum: 0a66 Address: 10.0.0.100 -> 192.168.0.200 Proto: icmp, type: 0, code: 0 Desc: Echo reply 64 bytes from 10.0.0.100 icmp_seq=1 ttl=63 time=101.947 ms cc:01:0b:c2:00:00 -> 00:50:79:66:68:05 IPv4, id: a575, length: 84, ttl: 63, sum: 0a60 Address: 10.0.0.100 -> 192.168.0.200 Proto: icmp, type: 0, code: 0 Desc: Echo reply VPCS[6]> p 10.0.0.100 -2 -c 1 00:50:79:66:68:05 -> cc:02:0b:c4:00:00 IPv4, id: a57b, length: 84, ttl: 64, sum: 094a Address: 192.168.0.200 -> 10.0.0.100 Proto: udp, len: 64, sum: 224d Port: 30135 -> 7 cc:01:0b:c2:00:00 -> 00:50:79:66:68:05 IPv4, id: a57b, length: 84, ttl: 63, sum: 0a4a Address: 10.0.0.100 -> 192.168.0.200 Proto: udp, len: 64, sum: 224d Port: 7 -> 30135 64 bytes from 10.0.0.100 udp_seq=1 ttl=63 time=36.606 ms VPCS[6]> p 10.0.0.100 -3 -c 1 00:50:79:66:68:05 -> cc:02:0b:c4:00:00 IPv4, id: a580, length: 60, ttl: 64, sum: 0968 Address: 192.168.0.200 -> 10.0.0.100 Proto: tcp, sum: 8c57, ack: 00000000, seq: 022a1b59, flags: S Port: 53285 -> 7 cc:01:0b:c2:00:00 -> 00:50:79:66:68:05 IPv4, id: a580, length: 40, ttl: 63, sum: 0a7c Address: 10.0.0.100 -> 192.168.0.200 Proto: tcp, sum: c753, ack: 022a1b5a, seq: 140e0f76, flags: SA Port: 7 -> 53285 00:50:79:66:68:05 -> cc:02:0b:c4:00:00 IPv4, id: a581, length: 52, ttl: 64, sum: 096f Address: 192.168.0.200 -> 10.0.0.100 Proto: tcp, sum: 9487, ack: 140e0f77, seq: 022a1b5a, flags: A Port: 53285 -> 7 Connect [email protected] seq=1 ttl=63 time=51.250 ms 00:50:79:66:68:05 -> cc:02:0b:c4:00:00 IPv4, id: a582, length: 108, ttl: 64, sum: 0936 Address: 192.168.0.200 -> 10.0.0.100 Proto: tcp, sum: 272e, ack: 140e0f77, seq: 022a1b5a, flags: PA Port: 53285 -> 7 cc:01:0b:c2:00:00 -> 00:50:79:66:68:05 IPv4, id: a582, length: 40, ttl: 63, sum: 0a7a Address: 10.0.0.100 -> 192.168.0.200 Proto: tcp, sum: c71c, ack: 022a1b92, seq: 140e0f77, flags: A Port: 7 -> 53285 SendData [email protected] seq=1 ttl=63 time=39.752 ms 00:50:79:66:68:05 -> cc:02:0b:c4:00:00 IPv4, id: a583, length: 52, ttl: 64, sum: 096d Address: 192.168.0.200 -> 10.0.0.100 Proto: tcp, sum: 9446, ack: 140e0f77, seq: 022a1b92, flags: FPA Port: 53285 -> 7 cc:01:0b:c2:00:00 -> 00:50:79:66:68:05 IPv4, id: a583, length: 40, ttl: 63, sum: 0a79 Address: 10.0.0.100 -> 192.168.0.200 Proto: tcp, sum: c71b, ack: 022a1b93, seq: 140e0f77, flags: A Port: 7 -> 53285 cc:01:0b:c2:00:00 -> 00:50:79:66:68:05 IPv4, id: a583, length: 40, ttl: 63, sum: 0a79 Address: 10.0.0.100 -> 192.168.0.200 Proto: tcp, sum: 053f, ack: 022a1b93, seq: 140e0f77, flags: FA Port: 7 -> 53285 Close [email protected] seq=1 ttl=63 time=55.080 ms VPCS[6]> 00:50:79:66:68:05 -> cc:02:0b:c4:00:00 IPv4, id: a584, length: 52, ttl: 64, sum: 096c Address: 192.168.0.200 -> 10.0.0.100 Proto: tcp, sum: 944d, ack: 140e0f78, seq: 022a1b93, flags: A Port: 53285 -> 7 VPCS[6]> relay dump off dump off I tested it on OSX. Attached is Linux program, but I can't find a Linux host which can be ran dynamips to test asymmetric routing.
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Author: | mirnshi [ Sun Oct 19, 2014 2:28 pm ] | ||
Post subject: | Re: vlan tagging issue with VPC | ||
Attached is pcap, packets between the routers.
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Author: | tasdevil [ Mon Oct 20, 2014 2:01 am ] |
Post subject: | Re: vlan tagging issue with VPC |
Thanks I have downloaded onto linux and can confirm the tagging between the routers is now as expected. Thank you. :) |
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