scornflake
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Creating multiple vlans on 3com 4200 28-port switches
I have 2 3Com 4200 28-port switches (Product #: 3C17304A) on which I'm trying to set up a few VLANS. I've outlined what, exactly, I need to do here: http://www.scornflake.com/examples/network.jpg
Basicly, my problem is that when I create, say vlan2 first, assign the ports to it, and connect the fiber, it works. When I add vlan 4 and it's respective ports, and connect the second fiber, it stops working. I wouldn't say it's looping as you'd expect if you just connected two redundant links at the same time without aggregation, but the second vlan is definitely not working. I've had it suggested that because the fiber links are only connecting the switches, that I need to make those ports something other than plain-old untagged member ports, as I've made the other 100mb ports in the vlan.
I'm just spewing all this out to try to get some dialog going, I'll be happy to provide any additional info I may have missed.
Thank you for any assistance you can provide.
Basicly, my problem is that when I create, say vlan2 first, assign the ports to it, and connect the fiber, it works. When I add vlan 4 and it's respective ports, and connect the second fiber, it stops working. I wouldn't say it's looping as you'd expect if you just connected two redundant links at the same time without aggregation, but the second vlan is definitely not working. I've had it suggested that because the fiber links are only connecting the switches, that I need to make those ports something other than plain-old untagged member ports, as I've made the other 100mb ports in the vlan.
I'm just spewing all this out to try to get some dialog going, I'll be happy to provide any additional info I may have missed.
Thank you for any assistance you can provide.
ASKER
I'm going to have to test it again, to tell you for sure what's happening. as I recall, vlan 2 continues to work, but vlan 4 does not. I've been reading about tagged vs untagged ports, and trunking. Would you recommend setting up a trunk for the fiber ports, or is this completely unnecessary? Also, regarding the tagging, I've left every port untagged, (as I understand it) as long as no port is included in more than one VLAN, untagged should be fine. Correct?
Your implementation, while slightly unusual, should work. The reason behind a tagged (or trunking) port would be if you wanted to carry multiple VLAN's over a single physical link. Since you're planning on a seperate link for each VLAN, you would not need a trunked link between the switches. However, you would have no redundancy should on of the link fail.
A more typical setup would be to eliminate the copper link off port 25 and make ports 27 and 28 tagged ports. Spanning Tree will block one of the links (probably port 28), but the remaining port will carry traffic for all VLANs.
A more typical setup would be to eliminate the copper link off port 25 and make ports 27 and 28 tagged ports. Spanning Tree will block one of the links (probably port 28), but the remaining port will carry traffic for all VLANs.
ASKER
If I were to make 27 and 28 tagged ports, how do I (or do I need to) setup tagging of packets in some way, or wil lthe switch do this automatically, depending on which vlan the packet originated?
Also, if I tag those two ports, I then have to include them within the scope of each of the vlans, (both 2 and 4), correct?
I'll have to look into the enabling of spanning ttree, that's not something I've used thus-far.
Thanks for your continued assistance.
Also, if I tag those two ports, I then have to include them within the scope of each of the vlans, (both 2 and 4), correct?
I'll have to look into the enabling of spanning ttree, that's not something I've used thus-far.
Thanks for your continued assistance.
ASKER
...also, if I do not enable spanning tree, I'll have to physically disconnect one of the fiber links so as to not create a loop, correct?
so, for example, vlan2 - ports 2-8, 27
vlan4 - ports 13-20, 27
port 27 would be tagged, 2-8 and 13-20 untagged.
and I could add:
vlan6 - ports 9-12, 21-24, 28 (the second fiber) all untagged, and eliminate port 26 (copper)
I understand this would be better setup using two fibers (on 27 & 28) and spanning tree, but considering I don't really know how to properly set that up, this would be simpler and still work, correct?
I do still need to know about the tagging question above, as well...
thanks
so, for example, vlan2 - ports 2-8, 27
vlan4 - ports 13-20, 27
port 27 would be tagged, 2-8 and 13-20 untagged.
and I could add:
vlan6 - ports 9-12, 21-24, 28 (the second fiber) all untagged, and eliminate port 26 (copper)
I understand this would be better setup using two fibers (on 27 & 28) and spanning tree, but considering I don't really know how to properly set that up, this would be simpler and still work, correct?
I do still need to know about the tagging question above, as well...
thanks
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When you say "it stops working", do you mean just traffic from VLAN2 between the switches? What about VLAN2 traffic within a switch? Does VLAN4 not come up?
You might try doing a continous ping between VLAN2 devices and see how long it takes after you connect the second fiber (VLAN4).