Miving from 10Mbps Switch to 100Mbps

[Jaco Barkhuizen]

One of my clients have recently decided to upgrade their switch from 10 to 10/100, but since 4 PC's can't access the server. Any suggestions where to start looking.

They are running Server 2003, with 6 XP machines (and 2 (Win98SE), of which one works fine but the other also can't log on)

[Ron Kinner]

I assume you have already done the obvious: Checked that everyone is in the same VLAN, that everybody has a link light on the switch, ruled out a speed mismatch, checked that ip address and masks are correct and there are no duplicates.

Can they ping the server?

Does

nslookup serversname
give you an IP address?

does nbtstat -a A.B.C.D
where A.B.C.D is the IP of the server give you the server's name? Does nbtstat -R or -RR help?

(A quick fix may be to edit the lmhosts file on each PC to add the server.)

Is there a WINS server involved? Does
ipconfig /all
show the correct gateway, DNS & WINS ?

Ron

[Thomas Bianco]

ron has most of the higher level stuff covered so i'll go with the lower level stuff.

lots of older network cards have problems with the 10-100 autodetect signals. this happened on some of our c-class PA Risc boxen, and we simply had to hard code the speed.

while i'm on duplex, this has also been known to cause problems. some cards may autodetect the speed, but ignore the duplex and use half reguardless. this is especially true of the older cards mention in the last paragraph. try hardcoding the port to half duplex.


ron- you're stealing all the good sugguestions. i'm going to get a post on a thread before you one of these days, even if i have to wake up at zero-dark thirty to check the boards. :P

[Pieter 't Hart]

W98 showed with us the problem that the login-screen was presented BEFORE the network-software was completely activated
so a log-on would fail.

Because of the autodetect/autonegotiate option AND the way switches work the workstations request for a DHCP-address would fail initially, so the logon was displayed without network available.

When a switch sees a port activated (workstation power on) the switch blocks traffic to/from that port for 30 seconds to see if there may be a possible loop in the network (key-word: spanning-tree)
only after that time data is passed to the port.

behaviour can be improved by disabling autodetect/autonegotiate (setting speed and duplex to fixed).
another improvement is to enable "portfast" on the switchport if the switch support this.
This results in normal traffic during thes first 30 seconds

hope this helps
Pieter

[Jaco Barkhuizen]

Thanx for your suggestions, I'll give a couple of things a try. (What happens is if we move them over to the new switch is that instead of the 2 lights, on the switch, coming on and blinking as traffic moves through, they only blink on/off slowly (I hope you get the idea))

I think I will try a few newer NIC cards and see if this solves the problem. Thanx

[Ron Kinner]

What kind of switch do we have? Is it one that has a management interface? Can you check the ports to see if they are shutdown? In Autonegotiate mode? Can you change them to 10 half?

Are we using house wiring? Are you sure that the cable is good? If you plug one of the working ones into the port /cable does it work OK? Note that 10baseT will work with only 2 pairs in the cable good. 100 baseT likes to have all 4 pairs.

Ron