public vlan on 3548-xl

[Zanne001]

I am trying to expand the public ips that are outward-facing at a client site. The isp router is a 2610. I created a vlan on the switch and one port is configured like this
interface FastEthernet0/4
duplex half
speed 10
switchport access vlan 20

I have set the speed on 3 ports to 10, and differing duplex settings. However, every time I connect the router, the line is admin up, protocol down. I ended up temporarily with a dumb hub connecting all my outward facing devices, and it works, but is not optimal. I can't think of what else that would keep the protocol down (even a vlan misconfiguration shouldn't do that) but was able to see the protocol come up on that switch only by disabling keepalives.

Perhaps it is obvious and I am just stupid?

 

[unclerico]

line speed and duplex settings won't keep the interface from coming up. If the line is up but the protocol is down then you have a layer 2 issue. Can you include a scrubbed config for the 2610 as well as the 3548??

I hate all Uppercase... I don't want my groups to seem angry at me all the time! =)
- ColdFlame (vbscript forum)

 

[burtsbees]

but was able to see the protocol come up on that switch only by disabling keepalives."
STP?

Burt

 

[vipergg]

Using a straight thru cable ? Verify by turning the cable ends over and put them side by side , the color codes should be exactly the same order . If you are using a crossover and the hub uses mdix that is why it might come up . 3549 does not support mdix so you would need a straight thru cable for a router to switch connection .

 

[Zanne001]

Thanks for the replies, so yes, I tried with both a straight thru and crossover to the interfaces with no love on the protocol. I am working remotely with a tech onsite who went out and purchased 3 crossover cables to test. I am kinda fuzzy on whether or not the protocol down refers ONLY to keepalives, or is also an encapsulation mismatch.

 

[vipergg]

Protocol down is a physical layer issue , it is not seeing the signal from the other end . If you are leaving it at 10/half then leave the switchports as auto . the switch port will default to 10/half .

 

[burtsbees]

I thought line protocol was layer 2...for example, try a ppp back to back config with either no clock on the DCE end or an encaps mismatch (ppp, hdlc)---line protocol will be down...right?

Burt