Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

  • Congratulations Mike Lewis on being selected by the Tek-Tips community for having the most helpful posts in the forums last week. Way to Go!

Switches with same IP address

Status
Not open for further replies.

Chopsy666

Technical User
Mar 11, 2005
59
GB
Hi,

I think we have two switches on the network with the same IP address. This makes telneting to it more dificult. However does anyone know if this could be the cause, or contribute to a slow network. As switches work at layer 2 i would have thought not, but perhaps i am looking at it too simplistically

Regards
Chopsy
 
Not 100% on this but in my experience you are warned that another device has the same IP address on the network and then wont assign the duplicate address!

What switches are they? I presume they are managed if you have assigned them IPs?

'When all else fails.......read the manual'
 
Thanks for the reply cyberspace.

Well when i try to telnet to the ip address, most of the time the console comes up with an HP 2424M, but sometimes a HP 4000M

Other times telnet simply wont connect at all.

the network here has kinda grown, and hence is not very well designed with some areas of the building having slower connectivity than others, and i was wondering whether switch configuration had something to do with it, and this is the first thing i have noticed.

 
Chopsy

Have you tried connecting upto the switches locally via a console/management port and checking the IP cfg that way. If you do have speed issues check link speeds and duplex settings while your there as well - the LED indicators should tell you port connection details.

HTH

Nogs
 
Hi Nogs,

I have done that and the IP config does appear a duplicate so i will change that.

I am getting the odd (ignore the date) :)

05/29/90 21:45:10 ports: port E6 in half duplex, flow control is auto-disable
05/29/90 21:45:10 ports: port E6 is now off-line
05/29/90 21:45:13 ports: port E6 is now on-line
05/29/90 21:45:40 ports: port E6 in half duplex, flow control is auto-disable
05/29/90 21:45:40 ports: port E6 is now off-line
05/29/90 21:45:42 ports: port E6 is now on-line

any ideas on why it would do this, as flow control is enabled on the ports. Mode is Auto and each port is 10/100TX

Regards
Chopsy

 
As far as I know the switches should have different IPs.

Ports are adaptive, if errors or connection issues occur the ports will downgrade. Possible causes, wires which are not up to CAT specs, as in crushed wire, poor termination, mis-wired pairs, bad NIC or driver; most likely the wires. The wires need to checked with a CAT certification test NOT an LED continuity tester.


........................................
Chernobyl disaster..a must see pictorial
 
They have to have different addresses if they are managed in the same subnet . I would just ping an address one above or below and see if anything responds unless you have someone who keeps track of this stuff . generally with modern switches , slow response is generally a layer 1 issue , so check your connecting links to make sure they are configured exactly the same on each end . This holds true for client connections also , if the client nic is set as auto then the switchport must be auto as well ,if hardcoded then the switch must be hardcoded .
 
Thanks for your help guys. I will have a looksy and see how it goes
 
Do you guys know if the following counters seem 'healthy', in terms of Broadcasts/Multicast transmissions. should they be so high or does the relation to bytes transmitted seem reasonable.

Name :

Link Status : Up

Bytes Rx : 455,920,451
Bytes Tx : 1,660,238,275
Unicast Rx : 1,811,955
Unicast Tx : 4,570,576
Bcast/Mcast Rx : 26,364
Bcast/Mcast Tx : 70,803,109

FCS Rx : 0 Drops Rx : 0
Alignment Rx : 0 Collisions Tx : 0
Runts Rx : 0 Late Colln Tx : 0
Giants Rx : 0 Excessive Colln : 0
Total Rx Errors : 0 Deferred Tx : 0

Thanks
 
Hi Choppsy

I would say that looks fine, if after adding new users further down the line you notice performance issues and the percentage of broadcasts has escalated you may need to then divide your broadcast domain by adding a router or implementing VLANs. For now though I see no problems with the figures you have given

Nogs
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor

Back
Top