Can't ping through a 2950

[Geoc]

I have a 2950 connected via GBIC to a 3550. which, in turn, is connected to a port on an older 4224.

I have 19 hosts connected to the 2950.

I have 6 hosts connected to the 4224 in two VLANS (vlan2 & vlan3)

The 3550 & 2950 are part of VLAN 3.

From the 2950, I can ping any and all switches and hosts connected.

From the hosts connected to the 2950, I can't ping beyond the 2950.

From the 3550, the 4224, or the hosts on the 4224, I can ping the 2950, but none of the hosts connected to it.

VLAN 3 is a /16 subnet, with the IP address of the vlan in the 4224 as the default gateway for all nodes on that vlan.
I'm sure there's something basic and/or obvious I'm overlooking here, but can't seem to discover what it is . . .

 

[RookThis]

How are the hosts on the 2950 getting their IPs, DHCP or static? If DHCP are they actually getting an ip and do they have a default router set? Are they on VLAN 3 as the 2950?

When you say you can't ping beyond the 2950, can you ping the 2950's IP or better yet can you ping the default router IP?

 

[Geoc]

No routers in the mix. The only layer 3 piece is the old 4224 at the "other end" of the network.

The 2950 is where the two (so far) VLANS originate.

The connectivity is more or less like this:

Six servers in two vlans --> Catalyst 4224 --> 3550 --> 2950(via GBIC Fiber Link) --> Network Clients (hosts connected to the 2950 ports)

I can ping the 2950's IP from anywhere.
I can ping all other IPs from anywhere BUT the network clients connected to the 2950.

ALL 2950 connected hosts have static IP's in the VLAN 3 (x.y.0.0/16)Subnet. In fact, everything has a static IP (These networks, btw, are part of an air-gapped training lab environment -- what little DHCP pools we require in this environment is handled by the Servers.)

 

[Geoc]

Correction: the VLANS are created in the 4224 . . .

 

[RookThis]

I'm still confused... from a host hanging off the 2950, can you ping the IP address of the gateway (4224) or ping the IP of the 3550?

 

[RookThis]

What vlan do you have assigned to the hosts on the 2950? Can you set one of the hosts to VLAN 3 if you do not have set that way.

 

[vipergg]

Post the 2950 config. Also you can check to see if the vlans on the 2950 were created right . Do a "show vlan" , this will show you all active vlans and what ports are assigned to these vlans . What address space is the management ip address of the 2950 in ??? Is this address part of vlan 3 ?

 

[Geoc]

From a host hanging off the 2950, I can ping ONLY the 2950, and, of course, the other hosts connected to the 2950: nothing beyond that.
Actually, RookThis, I'm not quite sure what you mean by assigning a VLAN to the hosts. If you mean they have IP addresses within the 2950's VLAN address space, yes.
The VLAN in question on the 4224 (VLAN 3, in this case) is the same for all ports on the 3550 and the 2950. I can't post the config right now (I'm not at work) but, again, all the ports in the 3550 and 2950 are configured for access to VLAN 3. The IP addresses for the VLANs are:
4224: x.y.0.254 (also the gateway address)
3550: x.y.0.252
2950: x.y.0.250

"show vlan" on the 2950 shows all ethernet ports on VLAN 3.
vlan 1 is administratively shut down.
There's also an administratively shut down vlan 101.

The GBIC ports are "native trunk" configured.

 

[RookThis]

What mask are you using on the hosts? what mask are you using on the 4224 interace for VLAN3?

 

[Geoc]

VLAN 3 Mask = 255.255.0.0

 

[RookThis]

Vipergg hit the nail on the head... post the configs... you are only giving bits and pieces and it's hard to figure out what you have.

 

[Geoc]

Got it fixed -- turned out to be the gig0/1 config on the 2950.
Was net for switchport mode trunk, and shouldn't have been.
Sorry 'bout not getting around to posting the configs . . .

Was chasing this beast from several directions. I'm sure if I posted the configs here first, the same discovery would have been made.

Thanx.