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Ethernet Switches & Routers

New Contributor
Posts: 3
Registered: ‎01-19-2011

Unable to Manage / Telnet Switches.


This is rather embarrassing, and I can’t find for the life of me a detailed explanation.

I had 3 x fcx634 switches in a stack, all configured.   I could telnet them without issue.  Each has a single rj45 cable in the out of band management port.

I have erased the configuration of them all, and rebooted.  All now have IP addresses off the dhcp server that lives on the out-of-band network.  Each switch has an IP address, and I can see them in DHCP.  I can ping them.

I cannot telnet them, or browse them, and if I port scan them tcp 23 is down.  However, all the documentation stats that there are no telnet password by default, and this is how I recalled it, before they where in a stack.

I should imagine this is how they should work.  Send a switch to site, it gets a reservation, telnet in without a p/w and then lock it down.

So am I missing a trick?  I can ping them, I cannot telnet them.  The config it empty (through the serial cable) except for the dynamic address they got from dhcp.

Nothing is in ports 1-24, but nothing ever was and I could telnet them.  All the switches report management 1 to be up.

Empty switches, all with dhcp addresses, all pingable, what am I missing.

Thanks in advance.

New Contributor
Posts: 3
Registered: ‎05-17-2011

Re: Unable to Manage / Telnet Switches.


Out of curiosity, what happens if you actually configure the following manually, instead of using DHCP:

ip address

ip subnet

default gateway

save configuration

I saw one posting where saving the config helped, actually the user reconfigured the admin password and saved the configuration, then was able to access the switch again.

Seeing as you have console access this should not take much time.



New Contributor
Posts: 3
Registered: ‎01-19-2011

Re: Unable to Manage / Telnet Switches.

This has been resolved.

It would appear the customer had a firewall on the router, for the management network, that allowed icmp but nothing else, after prommising no firewalls at all.  Sorry for everyones trouble.

Thanks for mucking in brian.


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