Speed and bandwidth clarification

[p.caforio]

Dear All,

While analyzing my switching infrastructure I found the following strange values.

I have 2 HP Enclosures with 2 Cisco 3020 switches each.

On the first Enclosure, while showing one interface in the backplane I get:

GigabitEthernet0/1 is up, line protocol is up (connected)
  Hardware is Gigabit Ethernet, address is 0024.5139.0b01 (bia 0024.5139.0b01)
  MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Full-duplex, 1000Mb/s, link type is auto, media type is 1000BaseX

On the second Enclosure, while showing one interface in the backplane I get:

GigabitEthernet0/14 is up, line protocol is up (connected)
  Hardware is Gigabit Ethernet, address is 001a.e27b.a80e (bia 001a.e27b.a80e)
  MTU 1500 bytes, BW 10000 Kbit, DLY 1000 usec,
     reliability 255/255, txload 46/255, rxload 116/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Full-duplex, 1000Mb/s, link type is auto, media type is 1000BaseX

Both have 1000Mb/s of speed but the second shows an available bandwidth of 10Mbps.

Is it a problem or I'm misunderstanding something??

thanks,

Paolo

[Muhammad Thanveer]

Hello Friend,

Bandwidth is not speed, actually bandwidth is the capacity. Capacity in the sense, minimum capacity (in bits per second).

Can you share the interface configuration, so that we can understand it very clearly.

Please remove the config which you feel is secured.

BR

Thanveer

Please rate the helpful posts

[p.caforio]

This is the configuration where BW is 10Mbps:

interface GigabitEthernet0/14
 switchport access vlan 501
 switchport mode access
 speed 1000
 spanning-tree portfast
end

thanks,

Paolo

[Arunagiri Nallusamy · Accepted solution]

Hi Paolo,

I believe you have not hard coded the speed to 1000 on the interface Gig0/1 in the first enclosure. By default an interface bandwidth should be 1000000 Kbit. This is a known issue with the 3020  blade switches where incorrect bandwidth values are displayed for ports where speed is hardcoded.

Bug:CSCsg28384 was filed for this behaviour. It was a duplicate of Bug:CSCsf31090 and the fix for this issue has been commited into IOS versions 12.2(35)SE and above. Hence I woould suggest to upgrade the code to any of the fixed version and recheck this behaviour.

I hope this helps.

Thanks,

Arun
 

[glen.grant]

   I suspect it's some kind of statistic representation bug .  If it's bothersome open a TAC case and point it out.  Check to see if the version is exactly the same on both switches.