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switching issue
http://forum.gns3.net/topic11900.html
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Author:  andrewculda [ Sat Sep 06, 2014 8:46 am ]
Post subject:  switching issue

Hi

I have a problem with my switch topology and i'm not sure if i'm missing something here, or it's just a bug.
i have a four-switch topology and i have no communication between two vpcs stations connected to different switches when the trunking encapsulation between switches is n-isl, unless they are in vlan 1. As soon as i move both of them in another vlan, they stop communicating. If i switch all trunks to dot1q, the problem goes away. I'm using the latest GNS3 version (beta2). Am i missing something ordinary here?

Thanks

Author:  rednectar [ Mon Sep 08, 2014 11:22 am ]
Post subject:  Re: switching issue

I grabbed a pen a paper and tried to draw your scenario, but didn't have enough information. What kind of switches? Generic Switches? IOS Switches? IF IOS, what version... to many unknowns

Author:  andrewculda [ Mon Sep 08, 2014 3:58 pm ]
Post subject:  Re: switching issue

i86bi-linux-l2-adventerprise-15.1b
Every switch with two connections to each other switch (full mesh).

Attachments:
topology.png
topology.png [ 31.47 KiB | Viewed 7079 times ]

Author:  rednectar [ Wed Sep 10, 2014 6:45 am ]
Post subject:  Re: switching issue

OK. I now have a picture - apart from the ports the VPCs are. But still not enough information.

What is the output (on each switch) of:
show spanning-tree blocked ports
show interface trunk
show interface status

Also it worries me that you have multiple links between switches in case you are tempted to do port channel (or ether channel) which I believe doesn't work with IOU (or IOS on the NM-ESW16 for that matter)

Author:  max [ Tue Sep 16, 2014 1:19 pm ]
Post subject:  Re: switching issue

Yes, also i. I have a problem with same switch topology. My image is i86bi-linux-l2-ipbasek9-15.1a.bin. I've noticed that when IOU1 is down, is all OK but when it is UP a lot PING failed ... I have Etherchannel L2 ... Is it BUG????

Thanks
Bye guys

Author:  mweisel [ Tue Sep 16, 2014 4:30 pm ]
Post subject:  Re: switching issue

Lack of Cisco Inter-Switch Link (ISL) support is a known limitation with L2 IOL (http://www.routereflector.com/cisco/cisco-iou-web-interface/features-not-supported). Currently, you have a choice of 802.1Q VLAN trunks or 802.1Q VLAN trunks. :) (post37130.html#p37130).

Author:  max [ Tue Sep 16, 2014 4:52 pm ]
Post subject:  Re: switching issue

OK but I've same problem with 802.1Q VLAN trunks

Author:  mweisel [ Wed Sep 17, 2014 2:52 am ]
Post subject:  Re: switching issue

Quote:
OK but I've same problem with 802.1Q VLAN trunks

Interesting. I just created a lab to test this more thoroughly. Everything checks out fine with my configuration. I've attached a screenshot and a notepad file, with the lab configuration, for you to reference. FYI, I'm using Ubuntu Server for my IOU VM instead of the standard one provided by the GNS3 community. Shouldn't make a difference, though.

Attachments:
topic11900-config.txt [4.38 KiB]
Downloaded 259 times
topic11900-gns3-screen.png
topic11900-gns3-screen.png [ 346.88 KiB | Viewed 6976 times ]

Author:  max [ Fri Sep 19, 2014 9:27 am ]
Post subject:  Re: switching issue

... These are my topology and configuration files ... i don't know ...

Bye guys

Attachments:
configMyTopology.txt [10.34 KiB]
Downloaded 251 times
PC4.jpg
PC4.jpg [ 105.84 KiB | Viewed 6917 times ]
PC1.jpg
PC1.jpg [ 103.67 KiB | Viewed 6917 times ]
MyTopology.jpg
MyTopology.jpg [ 68.45 KiB | Viewed 6917 times ]

Author:  max [ Sat Sep 20, 2014 10:27 am ]
Post subject:  Re: switching issue

I noticed that replacing the VPCs with VMs, the problem of connectivity between different PC resolves and everything is OK. But I have yet to understand why.

Bye

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