3560s Letting me Down!

[newmarket25]

We had a new network installed around march. To save money, we used the catalyst Express 500s. We setup Cisco phones as well. 7 buildings, all connected with fiber. The data was rock solid, no issues at all, but the phones were another matter, very unstable. So we upgraded to 3560s. Now we are having the opposite problem, the phones are rock solid, but the data is not very dependable. In particular, we have two servers that are connected to different swithces, and the users continue to get disconnected from the siwtches. I have tried hard coding the speed and duplex, and replaced NIC cards and cables. Things go great for a week, and then trouble starts building slowly, and then it gets to the point where people are dropped every 10 or 15 minutes.

Could really use some help!

[nw.admin]

I have had some similar problems. You are having some collisions on your server port. I would start with clearing your counter on that int, start a continous ping and watch. I have some servers that just don't like to play nice when the port is set to "auto". For some reason my servers think they should negotiate at 1 gig speed even though the switch doesn't do it. I have had to set both the port and the NIC to 100 full and have had great success with that. Maybe you have tried this, but I didn't see it in the thread.

[newmarket25]

The collisions are probably because I have set the port to 100 Half. I have tried hard coding the NIC and server port to 100 Full, but I still have issues. I am going to pop in a brand new NIC with the very latest Win2003 drivers, and see if they will play nice.

Anything else you can think of, I am game to try!

[newmarket25]

This is the "sho span" for spanning tree stuff from the switch where both users and server are on the same switch. My server is port 23, set to 100/half, on advice from some cisco doc. Port 24 goes to a 2801 which is providing VOIP.

[t.stemarie]

For all of your non-trunk ports, issue the command 'switchport mode access' so the ports don't try to do dynamic trunking protocol.

[newmarket25]

What about one of my 3560s, on port 24, it is linked to a 3com switch. There is no configuration listed for the port. Should that be anything special?

[jackyoung]

Can you advise more on the 3Com issue ? Do you mean no config. in 3560 or 3Com ?

For the 100/Half, you can try auto then hard-code both side, if it still not matched, I believe the NIC in the server may be too old that only support 100/half. Don't config. one side auto and one side hard-code, they should match each other.

At the moment, I don't find any problem at the moment. May need to check more.

[newmarket25]

What I meant was the port on the 3560 that has the 3Com attached has nothing for a config. Is that OK? It's just printers and web surfers primarily, no phones, nothing important.

Both sides are hard coded to 100/Half.

I keep coming back to the 3560s because for years we functioned with 3Com switches, then went to CE500s. Never had problems with either. Then we popped in the 3560s and now we have problems with 2 of the servers.

[jackyoung]

IC, you only need to ensure the port to connect to the 3Com is binding to the correct VLAN w/ correct IP Address assignment (virtual & physical IP if it is HSRP) then it should be fine.

I think this question turn into complicated. If there is still the problem. Could you please provide updated config., diagram & problem details ?

[newmarket25]

Yes I will. I am running out the door for an hour. Here is "sho int count err" on one switch that has users connected:

Port Align-Err FCS-Err Xmit-Err Rcv-Err UnderSize

Fa0/1 0 0 0 0 0

Fa0/2 0 0 0 0 0

Fa0/3 0 0 0 0 10

Fa0/4 0 0 0 0 0

Fa0/5 0 0 0 0 20

Fa0/6 0 0 0 0 20

Fa0/7 0 0 0 0 0

Fa0/8 0 0 0 0 0

Fa0/9 0 0 0 0 10

Fa0/10 0 0 0 0 0

Fa0/11 0 0 0 0 0

Fa0/12 0 0 0 0 20

Fa0/13 0 0 0 0 10

Fa0/14 0 0 0 0 0

Fa0/15 0 0 0 0 0

Fa0/16 0 0 0 0 0

Fa0/17 0 0 0 0 0

Fa0/18 0 0 0 0 0

Fa0/19 0 0 0 0 30

Fa0/20 0 0 0 0 0

Fa0/21 0 0 0 0 10

[jackyoung]

It looks fine on the counter. Wait for your info.

[newmarket25]

OK, I don't have a network diagram yet. But, here is as best as I can "describe it". Users at location 1, are connected thru switch 1. This siwtch has a fiber port, which connects to swicth 2. (Switch 1 is a 3560 24 port POE, siwtch 2 is a 24 port 3560G with 4 ports of fiber). The users are on switch 1, the server is on switch 2. I have attached the "sho run" for each switch.

The server is on Port 15 on switch 2. The fiber from switch1 plugs into g0/27 on sitch2. There is another 3560 24 Port POE hanging off of switch2, on port 24, supporting connections in Building 3.

[dgahm]

Doug,

You should move your data vlan off of VLAN 1 to a new VLAN. Cisco always advises than VLAN 1 not carry user data. The reason is that most switch control traffic runs on VLAN 1. This includes CDP, VTP, DTP.

Since your voice traffic is solid, it is worth a try. I can post a port config if you need it.

Dave

[newmarket25]

Well, here is some ping info...see if this makes sense.

(All addressing begins with 192.168.1.x)

91 my base station, hangs off swithc # 1

106 another PC off switch 1

4 the server we keep disconnecting to, hangs off swithc 2 which is connected to switch1 with fiber

254 the def gateway which hangs off switch2

google.com well known search engine

these are the TTLs when running continuos ping from 91:

106 TTL 128

4 TTL 128

254 TTL 255

google TTL 236

does that matter?

when we lost connectivity, every device was answering pings, except for 4 (the server). it did not answer 2, then answered 1, then did not answer 2 more. we lost connectivity somewhere in there.

Let me know if this means anything at all.

[newmarket25]

Yes, please post a config. Thanks.

I am willing to try it!

[dgahm]

Here is a working IP phone port config from a 3560 with data VLAN 10 and voice VLAN 100.

vlan 10(will create VLAN 10 with default settings)

interface FastEthernet0/6

switchport trunk encapsulation dot1q

switchport trunk native vlan 10

switchport mode trunk

switchport voice vlan 100

srr-queue bandwidth share 10 10 60 20

srr-queue bandwidth shape 10 0 0 0

mls qos trust device cisco-phone

mls qos trust cos

auto qos voip cisco-phone

spanning-tree portfast

You will also need to modify the router subinterface:

encapsulation dot1q 10

Dave