10-21-2009 10:54 AM - edited 03-06-2019 08:14 AM
I just took over the management of a new switch and I saw this in the config.
IP HOST cdc 10.51.x.x
Anybody know what purpose this serves?
I saw this in cisco help but I still do not know what the use of this IP HOST is.
ip host
To define a static host name-to-address mapping in the host cache, use the ip host global configuration command. To remove the name-to-address mapping, use the no form of this command.
ip host name [tcp-port-number] address1 [address2...address8]
no ip host name address
Syntax Description
name
Name of the host. The first character can be either a letter or a number. If you use a number, the operations you can perform are limited.
tcp-port-number
(Optional) TCP port number to connect to when using the defined host name in conjunction with an EXEC connect or Telnet command. The default is Telnet (port 23).
address1
Associated IP address.
address2...address8
(Optional) Additional associated IP address. You can bind up to eight addresses to a host name.
Solved! Go to Solution.
10-22-2009 08:03 AM
John
"it has always worked on the device where it is configed. I was hoping it would work from another device."
Ahhh, i see :-)
Well you can get it work from another device but you need to configure the router/switch that has the ip host entry as a DNS server. So
R1
==
ip host oh3 192.168.10.1
int s0/0
ip address 192.168.5.1 255.255.255.252
ip dns server
R2
==
ip name-server 192.168.5.1
int s0/0
ip address 192.168.5.2 255.255.255.252
then from R2 you should be able to ping oh3.
So the ip host is used for local resolution on the router and also it can be used to resolve remote DNS queries but you must then configure the router as a DNS server.
Jon
10-21-2009 10:57 AM
John
From the router you could now
telnet cdc
ping cdc
and the router would substitute the name cdc with the IP address 10.51.x.x
Jon
10-22-2009 03:50 AM
There must be something else that is needed to make it work because I get no response to a ping to cdc.
10-22-2009 05:46 AM
Just tested on a router and it worked fine for me. When you say you get no response what happens if you simply ping the IP address ?
Jon
10-22-2009 06:26 AM
Does this only work on a router?
I found this on L2 switch.
I have since tried to duplicate it on my switch that I have on my desk; a cisco 3560g.
ip host jw 10.49.1.102
RT03 is our main router but the IP host jw is coded on the switch at my desk.
KBCOH1RT03#ping jw
Translating "jw"...domain server (255.255.255.255)
% Unrecognized host or address, or protocol not running.
10-22-2009 06:31 AM
John
An interface must be up and running with an IP address on it for this to work.
Edit - actually it looks like an interface just needs to be configured with an IP for it to work.
Jon
10-22-2009 06:57 AM
I tried it on the original switch where I found it but it does not work.
That IP address is assigned to a svi.
So I coded one on our backup router and that does not work either.
The interface to the LAN for our backup router is 192.168.1.254
So I coded ip host oh3 192.168.1.254 Don't know if this makes a difference but that address is the real address of an HSRP configed interface.
10-22-2009 07:09 AM
Can you post output of "sh hosts" from your backup router ?
Jon
10-22-2009 07:17 AM
KBCOH1RT04#sh hosts
Default domain is not set
Name/address lookup uses domain service
Name servers are 10.49.2.252, 10.49.2.253
Codes: UN - unknown, EX - expired, OK - OK, ?? - revalidate
temp - temporary, perm - permanent
NA - Not Applicable None - Not defined
Host Port Flags Age Type Address(es)
oh3 None (perm, OK) 0 IP 10.49.1.189
10-22-2009 07:25 AM
Okay, you have the same output as i do except mine works and yours doesn't.
Which IOS version are you using ?
Can you post full config of router ?
Jon
10-22-2009 07:32 AM
I cannot post the config but here is the ver.
C2800NM-IPBASE-M), Version 12.4(15)T9
10-22-2009 07:42 AM
John
I'm using 12.4 mainline but that should not make a difference.
I literally can fire up a router, configure an IP address on an interface (don't even need to bring it up), add an "ip host ..." entry and then when i type "ping
So unless there is something in your config that is stopping this i'm not sure what is happening.
Jon
10-22-2009 07:46 AM
Here is what I get
KBCOH1RT03#ping oh3
Translating "oh3"...domain server (255.255.255.255)
% Unrecognized host or address, or protocol not running.
10-22-2009 07:50 AM
Can you run the same command on KBCOH1RT04 ?
Jon
10-22-2009 07:54 AM
it has always worked on the device where it is configed. I was hoping it would work from another device.
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