I am in the process of connecting a 3512XL to a 2948G-L3 switch using
a GBIC connection. When I connect the cable to the 3512 I do not get a
link light and even if I do a "no shut" command on the intface config,
I still get no link. The 2948 show the interface up and the protocol
up. But the 3512 shows the interface down and the protocol down. This
is my first time working with GBIC, so any and all help is
appreciated.

Try reversing the connectors on one side (there needs to be a cross-over).

"Frank Toner" <ftoner@dewittstern.com> wrote in message
news:b4cfceda.0405060553.7124146f@posting.google.com...
> I am in the process of connecting a 3512XL to a 2948G-L3 switch using
> a GBIC connection. When I connect the cable to the 3512 I do not get a
> link light and even if I do a "no shut" command on the intface config,
> I still get no link. The 2948 show the interface up and the protocol
> up. But the 3512 shows the interface down and the protocol down. This
> is my first time working with GBIC, so any and all help is
> appreciated.

Frank,
I hate to state the obvious, but did you cross the TX and RX.
I am guessing that you have TX to TX and RX to RX.
With the fiber in between, you will need to cross them.

Hope this helps,
Roger L
http://www.sellusedcisco.com
Your best option and price for selling used Cisco equipment!

"Frank Toner" <ftoner@dewittstern.com> wrote in message
news:b4cfceda.0405060553.7124146f@posting.google.com...
> I am in the process of connecting a 3512XL to a 2948G-L3 switch using
> a GBIC connection. When I connect the cable to the 3512 I do not get a
> link light and even if I do a "no shut" command on the intface config,
> I still get no link. The 2948 show the interface up and the protocol
> up. But the 3512 shows the interface down and the protocol down. This
> is my first time working with GBIC, so any and all help is
> appreciated.

ftoner@dewittstern.com (Frank Toner) wrote in message news:<b4cfceda.0405060553.7124146f@posting.google.com>...
> I am in the process of connecting a 3512XL to a 2948G-L3 switch using
> a GBIC connection. When I connect the cable to the 3512 I do not get a
> link light and even if I do a "no shut" command on the intface config,
> I still get no link. The 2948 show the interface up and the protocol
> up. But the 3512 shows the interface down and the protocol down. This
> is my first time working with GBIC, so any and all help is
> appreciated.


Yeah the reversal on the links was an obvious one, but I still am not
seeing gig0/1 and 0/2 as part of the vlan 1 even though I have them
set to switchport trunk mode. I have link on both sides now but still
cannot ping the 2948 from the 3512.

Frank,
I would next try swapping the GBICs and see if the symptoms follow; if you
have not done that already. Or at least swap out the ends of the cable to
rule that out.

Other than that I would put the 3512 in suspect.  They have had a high rate
of failure(one of the reasons that they were EOL so fast).


--
Hope this helps,
Roger L
http://www.sellusedcisco.com
Your best option and price for selling used Cisco equipment!


"Frank Toner" <ftoner@dewittstern.com> wrote in message
news:b4cfceda.0405070631.48ae5be6@posting.google.com...
> ftoner@dewittstern.com (Frank Toner) wrote in message
news:<b4cfceda.0405060553.7124146f@posting.google.com>...
> > I am in the process of connecting a 3512XL to a 2948G-L3 switch using
> > a GBIC connection. When I connect the cable to the 3512 I do not get a
> > link light and even if I do a "no shut" command on the intface config,
> > I still get no link. The 2948 show the interface up and the protocol
> > up. But the 3512 shows the interface down and the protocol down. This
> > is my first time working with GBIC, so any and all help is
> > appreciated.
>
>
> Yeah the reversal on the links was an obvious one, but I still am not
> seeing gig0/1 and 0/2 as part of the vlan 1 even though I have them
> set to switchport trunk mode. I have link on both sides now but still
> cannot ping the 2948 from the 3512.

"Frank Toner" <ftoner@dewittstern.com> wrote in message
news:b4cfceda.0405070631.48ae5be6@posting.google.com...
> ftoner@dewittstern.com (Frank Toner) wrote in message
news:<b4cfceda.0405060553.7124146f@posting.google.com>...
> > I am in the process of connecting a 3512XL to a 2948G-L3 switch using
> > a GBIC connection. When I connect the cable to the 3512 I do not get a
> > link light and even if I do a "no shut" command on the intface config,
> > I still get no link. The 2948 show the interface up and the protocol
> > up. But the 3512 shows the interface down and the protocol down. This
> > is my first time working with GBIC, so any and all help is
> > appreciated.
>
>
> Yeah the reversal on the links was an obvious one, but I still am not
> seeing gig0/1 and 0/2 as part of the vlan 1 even though I have them
> set to switchport trunk mode. I have link on both sides now but still
> cannot ping the 2948 from the 3512.

OK, your confusing me.  Do you have both of these gig ports (g0/1 & g0/2)
connected to the same 2950?  If these are both connected to the same switch
then spanning tree is doing it's job and blocking you can issue the show
spanning-tree interface g0/1 to display it's spanning-tree state.

If you have configured the ports to trunk you will not see the ports in the
show vlan output.  You need to use the command show interface trunk to see
trunking ports.

As far as being able to ping that falls into layer three which the 3512 may
or may not be doing.

-Jeff C