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ntp services on a 2912XL Switch

Hi folks,

I have a small home network consisiting of a cable modem, PIX 501 firewall and a 2912XL Cat Switch (running 12.05 Enterprise Edition software).

I can't get npt to work on my Cat swtich. The PIX firewall is working fine and locked to the public servers I have specified. The switches however show "insane, invalied..." etc indicating they cannot see the public time servers specified (exactly the same servers as for the pix).

What am i doing wrong?

As a secondary question what is the best way to set this network up for ntp? Can the Cat switch act as an ntp client and also as a server to the PIX? (I know the PIX does not support ntp serving).

Thanks in advance for any advice or suggestions!




Re: ntp services on a 2912XL Switch

Is the switch able to ping the NTP servers or the Internet in general? There may be a routing issue (e.g., default gateway not configured properly).

Though I've never tried using a 2912 as an NTP server (only 2950's and up), generally Cisco devices can act as both NTP clients and NTP servers. This allows for a heirarchical NTP setup which is the recommended practice in most situations. Typically, one or more devices at the edge of the network sync with a public NTP server and all other devices on the network sync with this device.


Re: ntp services on a 2912XL Switch

Thanks for that. Yes I can ping the ntp servers from the swtich. I know the PIX 501 does not support ntp serving. It appears that the 2912Xl should do so it seems sensible, as you suggest, to perhaps make it the master device and everything else could sync off it.


Re: ntp services on a 2912XL Switch

Maybe you can run some "debug ntp" (if the switch supports them) commands to get an idea of what the issue is.