Cisco 3750G switch issue

[kevintang]

HI,

I have two cisco 3750G switch. one of them is working fine (good performance) with the old 10MB/half interface device. But another 3750G switch has bad performance with the same old 10MB/half interface device. Both switch are running same latest IOS and same configuration on the interface. Any idea?

[royalblues]

Since the device is running at half duplex it may be receiving lot of collisions affecting the performance.

Do you see any difference in the interface statistics when connected to the good and bad 3750 switch.

Try Hardcoding the interface on the 3750 to 10 half which can eliminate negotiation problems.

HTH

Narayan

[kevintang]

Yes, we can see the difference. we have tried all possiable configuration the interface. but just one of them is better than another one.

===good one:====

Transmit GigabitEthernet1/0/17 Receive

576135912 Bytes 906812993 Bytes

110164320 Unicast frames 658437 Unicast frames

3448619 Multicast frames 3 Multicast frames

5880870 Broadcast frames 5080 Broadcast frames

0 Too old frames 905976508 Unicast bytes

294668 Deferred frames 192 Multicast bytes

0 MTU exceeded frames 828430 Broadcast bytes

218 1 collision frames 0 Alignment errors

186 2 collision frames 0 FCS errors

145 3 collision frames 0 Oversize frames

31 4 collision frames 0 Undersize frames

14 5 collision frames 1964 Collision fragments

10 6 collision frames

20 7 collision frames 29364 Minimum size frames

5 8 collision frames 24337 65 to 127 byte frames

12 9 collision frames 16837 128 to 255 byte frames

32 10 collision frames 1439 256 to 511 byte frames

12 11 collision frames 54 512 to 1023 byte frames

1 12 collision frames 591489 1024 to 1518 byte frames

0 13 collision frames 0 Overrun frames

0 14 collision frames 0 Pause frames

0 15 collision frames

0 Excessive collisions 0 Symbol error frames

0 Late collisions 0 Invalid frames, too large

0 VLAN discard frames 0 Valid frames, too large

0 Excess defer frames 1964 Invalid frames, too small

32300661 64 byte frames 0 Valid frames, too small

86450813 127 byte frames

241328 255 byte frames 0 Too old frames

122318 511 byte frames 0 Valid oversize frames

7459 1023 byte frames 0 System FCS error frames

371230 1518 byte frames 0 RxPortFifoFull drop frame

0 Too large frames

218 Good (1 coll) frames

468 Good (>1 coll) frames

[kevintang]

========bad one======================

Transmit GigabitEthernet2/0/17 Receive

1433768758 Bytes 2839558401 Bytes

216481351 Unicast frames 162234648 Unicast frames

17884645 Multicast frames 0 Multicast frames

7697564 Broadcast frames 41 Broadcast frames

0 Too old frames 2836524031 Unicast bytes

95797 Deferred frames 0 Multicast bytes

0 MTU exceeded frames 2624 Broadcast bytes

535176 1 collision frames 0 Alignment errors

82952 2 collision frames 0 FCS errors

14709 3 collision frames 3 Oversize frames

1362 4 collision frames 1 Undersize frames

40 5 collision frames 750853 Collision fragments

0 6 collision frames

0 7 collision frames 96320 Minimum size frames

0 8 collision frames 162132464 65 to 127 byte frames

0 9 collision frames 3216 128 to 255 byte frames

0 10 collision frames 2689 256 to 511 byte frames

0 11 collision frames 0 512 to 1023 byte frames

0 12 collision frames 0 1024 to 1518 byte frames

0 13 collision frames 0 Overrun frames

0 14 collision frames 0 Pause frames

0 15 collision frames

0 Excessive collisions 0 Symbol error frames

1 Late collisions 3 Invalid frames, too large

0 VLAN discard frames 7 Valid frames, too large

0 Excess defer frames 750853 Invalid frames, too small

88729000 64 byte frames 1 Valid frames, too small

93194636 127 byte frames

1976739 255 byte frames 0 Too old frames

1503897 511 byte frames 7 Valid oversize frames

1369413 1023 byte frames 0 System FCS error frames

55289876 1518 byte frames 0 RxPortFifoFull drop frame

0 Too large frames

535176 Good (1 coll) frames

99063 Good (>1 coll) frames

[sourabhagarwal]

can u hardset speed/duplex to 10/half on the swicth which is not giving good performance.

after that clear counters and see if things have changed for you or if it is still working the way it is working before.

[glen.grant]

You need to take a look at the device and see how the nic card is set if its auto/auto or hardcoded and then you have to match whatever the nic is set at . Is this a real old device , very few devices have to run at 10/half I would check to see if it will runn auto or can hardcode to 100/full .