Problem Accessing E2810 from different subnet

[Bob Hartung]

I just replaced an HP Procurve 2626 Switch at a remote facility with an HP Procurve E2810-48G. Everything appeared to be fine. I was able to access the E2810 web interface from a PC on the same subnet and change the IP address from DHCP to a manual fixed IP address. I used the same IP address as the old 2626.

When I returned to my office at another facility, I tried accessing the E2810 web interface and it timed out. I found I couldn't ping it either. I remoted into a PC at the remote facility and found I could still bring up the web interface using a pc on the same subnet.

Here is how the 2 facilities are connected...

My Location Cisco Router --- My Location Cisco Router --- My Location Solectek Wireless Bridge ----- Remote Location Solectek Wireless Bridge --- Remote Location Wireless Bridge

Here is a trace route to the E2810 ...

tracert 172.18.1.51

Tracing route to 172.18.1.51 over a maximum of 30 hops

  1     1 ms    <1 ms    <1 ms  172.16.254.254     --- My Location Main Cisco Router
  2     1 ms     1 ms     1 ms  172.16.254.253     --- My Location Cisco Router
  3     2 ms     2 ms     2 ms  192.168.100.2     --- Remote Cisco Router
  4     *        *        *     Request timed out.
  5     *        *        *     Request timed out.

Here is a trace route to another switch at the same remote facility...

C:\Users\rah.WISCOIND>tracert 172.18.1.52

Tracing route to 172.18.1.52 over a maximum of 30 hops

  1     1 ms    <1 ms     1 ms  172.16.254.254     --- My Location Main Cisco Router
  2     1 ms     1 ms     1 ms  172.16.254.253     --- My Location Cisco Router
  3     2 ms     2 ms     2 ms  192.168.100.2     --- Remote Cisco Router
  4     2 ms     2 ms     2 ms  172.18.1.52     --- Remote HP Switch

Trace complete.

I've checked the Remote Facility Cisco Router ARP table and it shows the correct MAC address associated with the E2810 for the IP address.

Is there something about the E2810 security that blocks access from another subnet?

Any help would be appreciated.

Thanks.

[paulgear]

The most likely candidates are a routing issue on the E2810, and a security configuration which prevents some traffic. Routing is usually the problem when i see this, but if you post a copy of the switch config (using "show run" from the CLI, i'm sure we'll be able to work it out.

[Bob Hartung]

Turns out, the problem was a missing entry in the default gateway field on the e2810. I originally powered up the unit at my location. By default, DHCP is enabled so it came up fine and worked.

When I brought the e2810 to the remote facility, I powered it up with DHCP endabled and it worked fine again.

My mistake was using the web interface to change the IP address to a manually assigned number. On that screen, the only entry is the IP number. It didn't occur to me that the default gateway value is reset to null doing that.

My recommendation to HP would be to either remove the ability to assign an IP through the web interface or make it more comprehensive, including both the default gateway and subnet mask values.;

For my part, I'll use telnet for initial network configuration tasks. However, telnet is less convenient these days since Microsoft dropped HyperTerm.

Thanks.

[paulgear]

Do yourself a favour and download putty (http://www.chiark.greenend.org.uk/~sgtatham/putty/) - it has a lot more features than Windows telnet, and can do ssh as well, which is the best way to connect to the switch's CLI.