Ben,

*  The port on the 3560, going to the firewall, has the following
config:  no switchport   ip address 192.168.1.2 255.255.255.0

*  I agree on the link lights, which is why the original MDI-X comment
wasn't a concern for me.

*  There shouldn't be any VLAN issues with the port to the firewall,
since there aren't any at that point.  The VLANS are on the HP 4108
only, and communicated to the LAN port of the router, which will soon be
port 24 on the Cisco.

*  I've also tried to ping the Cisco from my desktop, which should
qualify as external equipment, with no joy.

*  "The way they were" in this instance means my 2651 router's LAN port
connected to the "Trunk" port of the HP. (Meaning the port that is
TAGGED for all the VLANS, no port aggregation taking place - no HP
"trunks" involved).  And the external port of the router plugged into
the firewall.  As far as the other details, I'm not changing anything
right now, I just want the 3560 switch to act exactly like the 2651
router acts now.  There are no VLAN changes, no IP changes, nothing.
All of that will come down the road when I get rid of all the public IP
subnets we're currently using inside our network, and along with that,
get rid of all the VLANS.

*  As far as the ping responses, my thoughts are that as soon as the
Cisco switch and the HP switch start talking to each other, all of that
will go away.

I am greatly concerned that the HP switch does not detect the MAC
address of the Cisco switch when they are connected.  That is telling me
that the HP does not see any device connected to that port.  I've tried
multiple, brand new patch cables, so it's not that.


As mentioned before, I'm more than happy to send all 3 config files to
anyone that is willing to take a look at them to see if there's
something that I've missed.  I'm in no way an expert on configuring
Cisco, as this is the first layer 3 from them that I've played with.

Thanks again, and if there's any other info you need, just let me know.
As far as the unmanaged switch, and testing stuff, I will make note of
it, and possibly try that the next time I can bring the network down for
this.


Joe Heaton

-----Original Message-----
From: Ben Scott [mailto:[EMAIL PROTECTED] 
Sent: Monday, February 11, 2008 12:20 PM
To: NT System Admin Issues
Subject: Re: Help with HP/Cisco switch communication

[responses inline; quotes re-ordered for editorial purposes]

On Feb 11, 2008 11:20 AM, Joe Heaton <[EMAIL PROTECTED]> wrote:
> *  I get green link lights on all ports. (Except firewall, which gives

> me a yellow Gig link light)

  If you're getting link lights, then the MDI polarity is not your
problem.  (If there was an MDI polarity mismatch, the ports wouldn't
link at all.)

> I cannot ping the Cisco from inside the HP.
> I log into the firewall, and cannot ping the 192 address of the Cisco
port.
> I console into the Cisco, and cannot ping in either direction.

    Keep in mind that the switch's internal IP addresses are also
subject to VLANs.  If your firewall is plugged into a port configured to
be just VLAN 5, but the IP address of the Cisco is associated with just
VLAN 2, the firewall will not be able to ping the switch's IP address.
VLANs work just like physical LANs -- if they're not connected, no
traffic will flow.

  You may want to use external equipment (i.e., an independent
computer) for the ping tests.  That saves you the trouble of having to
figure out how to configure the switch's management IP addresses and
VLANs to work together all at once.

> *  I put things back the way they were, and everything works.

  We don't know what "the way they were" means here.  Describe physical
topology, any link aggregation, VLAN assignments, IP address
assignments, and IP routing plan.  Do likewise for "the way you want
things to be".  Post both descriptions here.

  It is entirely likely that, once you get done writing out all the
above for us, you'll see the problem and won't need our help anymore.
:-)

> *  From my desk, the persistent pings I've had going to the remote 
> site servers are now alternating between Destination Host Unreachable,

> and Request timed out.

  It sounds like you've got multiple issues.  You've certainly got
multiple points where problems could be.  You need to isolate the
trouble.

  One possible plan of attack:

  If you're not using VLAN tagging on the Ethernet link to the firewall,
get a small unmanaged switch and put it between the firewall and
whatever the firewall is normally plugged into.  (You'll see why in a
minute.)  Make sure that doesn't disrupt things.  (If the firewall is
VLAN aware and expecting to add/decode VLAN tags in its Ethernet frames,
this whole idea is invalid.  Yell if that's the
case.)

  Configure a test computer with appropriate manual IP address, route,
etc.  Plug it into the unmanaged switch.  See if if you can ping the
firewall.  If you can, see if you can ping the next hop beyond the
firewall.  This gives us a known-good to start testing with.

  Next, configure a port on the Cisco to be on the same VLAN as the port
for the firewall.  Plug that unmanaged switch into firewall's port on
the Cisco, as if it was the firewall itself.  Plug the test computer
into the other port we just configured.  Run those tests again.  If this
doesn't work, there is a problem with the config on the Cisco.  Get that
sorted out before moving on.

  Next, configure a likewise test port on the HP, connect the HP to the
Cisco, and plug the test computer into the HP and test.  If that doesn't
work, the problem is either on the HP, or between the HP and the Cisco.
If you get to that, try plugging that unmanaged switch into a third port
on the HP, all configured with appropriate VLANs, and see if you can
ping through just the HP.  If that works, you know the issue is with the
inter-switch link.

-- Ben

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