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!

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

Question network switch cisco 2950

Status
Not open for further replies.
P4zz3o

P4zz3o

IS-IT--Management
May 14, 2010
5
IT
Hello guys,

I have a strange situation in my lan with 2 switch cisco 2950, with almost all port used (some ports are 10M half (old pc connected) and others are 100M full). The 2 switch have 3 vlan and they are in thrunk.

What happens? ---> For some computer in the same vlan, I see a lot of retrasmission packets.. Is it possible to reduce them?
If I try to use ping, I don't see no packets lost.

Why have I a lot of retrasmission packets? Could it depends by the switch? Is it possible to see if there is some problems in the switch?
Maybe I could install SDM, but I don't know if it is compatible with these version of switch....

Thank you in advance,

P4zz3o
 
Sort by date Sort by votes
SDM is not compatible with switches. Post a sh interface of the switchport(s) the device(s) is/are connected to. Sounds like a duplex mismatch to me. You'll have to hardcode both ends to 10/half---auto will likely not work.

/

tim@tim-laptop ~ $ sudo apt-get install windows
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Couldn't find package windows...Thank Goodness!
 
Upvote 0 Downvote
hello burtbees,

This is the result of sh interfaces status
Code: 
 Fa0/1     FREE               connected    1          a-half   a-10 10/100BaseTX
Fa0/2     FREE               notconnect   1            auto   auto 10/100BaseTX
Fa0/3     FREE               notconnect   1            auto   auto 10/100BaseTX
Fa0/4     FREE               notconnect   1            auto   auto 10/100BaseTX
Fa0/5     FREE               connected    2          a-half  a-100 10/100BaseTX
Fa0/6     FREE               connected    2          a-full  a-100 10/100BaseTX
Fa0/7     FREE               notconnect   2            auto   auto 10/100BaseTX
Fa0/8     FREE               notconnect   2            auto   auto 10/100BaseTX
Fa0/9     FREE               connected    2          a-half  a-100 10/100BaseTX
Fa0/10    FREE               notconnect   2            auto   auto 10/100BaseTX
Fa0/11    PC_1		     connected    3          a-full  a-100 10/100BaseTX
Fa0/12    PC_2	             connected    3          a-full  a-100 10/100BaseTX
Fa0/13    FREE 		     connected    3          a-full  a-100 10/100BaseTX
Fa0/14    FREE		     connected    3          a-half   a-10 10/100BaseTX
Fa0/15    FREE               connected    3          a-half   a-10 10/100BaseTX
Fa0/16    FREE		     connected    3          a-half   a-10 10/100BaseTX
Fa0/17    FREE		     connected    3          a-full  a-100 10/100BaseTX
Fa0/18    FREE               notconnect   3            auto   auto 10/100BaseTX
Fa0/19    FREE               connected    3          a-full  a-100 10/100BaseTX
Fa0/20    FREE               connected    3          a-full  a-100 10/100BaseTX
Fa0/21    PC_START           connected    3          a-half   a-10 10/100BaseTX
Fa0/22    FREE               notconnect   3            auto   auto 10/100BaseTX
Fa0/23    TRUNK to SW1 port  connected    trunk      a-full  a-100 10/100BaseTX
Fa0/24    TRUNK to SW1 port  connected    trunk      a-full  a-100 10/100BaseTX [\code]
 
Upvote 0 Downvote
Sorry,

Forgot my last post, i click submit faster.
Code: 
Fa0/1     FREE               connected    1          a-half   a-10 10/100BaseTX
Fa0/2     FREE               notconnect   1            auto   auto 10/100BaseTX
Fa0/3     FREE               notconnect   1            auto   auto 10/100BaseTX
Fa0/4     FREE               notconnect   1            auto   auto 10/100BaseTX
Fa0/5     FREE               connected    2          a-half  a-100 10/100BaseTX
Fa0/6     FREE               connected    2          a-full  a-100 10/100BaseTX
Fa0/7     FREE               notconnect   2            auto   auto 10/100BaseTX
Fa0/8     FREE               notconnect   2            auto   auto 10/100BaseTX
Fa0/9     FREE               connected    2          a-half  a-100 10/100BaseTX
Fa0/10    FREE               notconnect   2            auto   auto 10/100BaseTX
Fa0/11    PC_1		     connected    3          a-full  a-100 10/100BaseTX
Fa0/12    PC_2	             connected    3          a-full  a-100 10/100BaseTX
Fa0/13    FREE 		     connected    3          a-full  a-100 10/100BaseTX
Fa0/14    FREE		     connected    3          a-half   a-10 10/100BaseTX
Fa0/15    FREE               connected    3          a-half   a-10 10/100BaseTX
Fa0/16    FREE		     connected    3          a-half   a-10 10/100BaseTX
Fa0/17    FREE		     connected    3          a-full  a-100 10/100BaseTX
Fa0/18    FREE               notconnect   3            auto   auto 10/100BaseTX
Fa0/19    FREE               connected    3          a-full  a-100 10/100BaseTX
Fa0/20    FREE               connected    3          a-full  a-100 10/100BaseTX
Fa0/21    PC_START           connected    3          a-half   a-10 10/100BaseTX
Fa0/22    FREE               notconnect   3            auto   auto 10/100BaseTX
Fa0/23    TRUNK to SW1 port  connected    trunk      a-full  a-100 10/100BaseTX
Fa0/24    TRUNK to SW1 port  connected    trunk      a-full  a-100 10/100BaseTX



The port PC_1 and PC_2 receive the traffic form PC_START. Only in this way I see re-trasmission packets.

in details:

Code: 
FastEthernet0/21 is up, line protocol is up (connected)
  Hardware is Fast Ethernet, address is 0012.7f9c.f2d5 (bia 0012.7f9c.f2d5)
  Description: PC_START
  MTU 1500 bytes, BW 10000 Kbit, DLY 1000 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Half-duplex, 10Mb/s, media type is 100BaseTX
  input flow-control is unsupported output flow-control is unsupported
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input never, output 00:00:00, output hang never
  Last clearing of "show interface" counters 15w5d
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 1000 bits/sec, 1 packets/sec
  5 minute output rate 1000 bits/sec, 1 packets/sec
     1995243 packets input, 178076787 bytes, 0 no buffer
     Received 1199 broadcasts (0 multicast)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 0 multicast, 0 pause input
     0 input packets with dribble condition detected
     10333937 packets output, 3603499060 bytes, 0 underruns
     0 output errors, 72 collisions, 0 interface resets
     0 babbles, 0 late collision, 527 deferred
     0 lost carrier, 0 no carrier, 0 PAUSE output
     0 output buffer failures, 0 output buffers swapped out

Code: 
FastEthernet0/11 is up, line protocol is up (connected)
  Hardware is Fast Ethernet, address is 0012.7f9c.f2cb (bia 0012.7f9c.f2cb)
  Description: PC_1
  MTU 1500 bytes, BW 100000 Kbit, DLY 1000 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Full-duplex, 100Mb/s, media type is 100BaseTX
  input flow-control is unsupported output flow-control is unsupported
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input never, output 00:00:00, output hang never
  Last clearing of "show interface" counters 15w5d
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 16000 bits/sec, 27 packets/sec
  5 minute output rate 287000 bits/sec, 28 packets/sec
     137251554 packets input, 1710164145 bytes, 0 no buffer
     Received 1494 broadcasts (0 multicast)
     0 runts, 0 giants, 0 throttles
     1 input errors, 0 CRC, 1 frame, 0 overrun, 0 ignored
     0 watchdog, 25 multicast, 0 pause input
     0 input packets with dribble condition detected
     183355431 packets output, 1671369679 bytes, 0 underruns
     24 output errors, 18 collisions, 0 interface resets
     0 babbles, 24 late collision, 39 deferred
     0 lost carrier, 0 no carrier, 0 PAUSE output
     0 output buffer failures, 0 output buffers swapped out



FastEthernet0/12 is up, line protocol is up (connected)
  Hardware is Fast Ethernet, address is 0012.7f9c.f2cc (bia 0012.7f9c.f2cc)
  Description: PC_2
  MTU 1500 bytes, BW 100000 Kbit, DLY 1000 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Full-duplex, 100Mb/s, media type is 100BaseTX
  input flow-control is unsupported output flow-control is unsupported
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 1y17w, output 00:00:00, output hang never
  Last clearing of "show interface" counters 15w5d
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 1000 bits/sec, 1 packets/sec
  5 minute output rate 280000 bits/sec, 27 packets/sec
     14243610 packets input, 1306397097 bytes, 0 no buffer
     Received 79 broadcasts (0 multicast)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 0 multicast, 0 pause input
     0 input packets with dribble condition detected
     206544612 packets output, 4158931892 bytes, 0 underruns
     0 output errors, 0 collisions, 0 interface resets
     0 babbles, 0 late collision, 0 deferred
     0 lost carrier, 0 no carrier, 0 PAUSE output
     0 output buffer failures, 0 output buffers swapped out



Regards,

P4zz30
 
Upvote 0 Downvote
I tested again, and all traffic from and to the port has the problem of re-trasmission tcp packets.
 
Upvote 0 Downvote
100/full transmitting to 10/half you are going to get a lot of retransmissions due to the duplex mismatch...

"24 late collisions"

Are these the only duplex mismatch communications that are occuring, i.e. are any other 10/half communicating with any other 100/full?

Looks like changing the NIC to a 100/full card will solve your problem.

/

tim@tim-laptop ~ $ sudo apt-get install windows
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Couldn't find package windows...Thank Goodness!
 
Upvote 0 Downvote
Or change the pc1 and pc2 NICs to 10/half AND hardcode the 2950 switchports to 10/half.

/

tim@tim-laptop ~ $ sudo apt-get install windows
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Couldn't find package windows...Thank Goodness!
 
Upvote 0 Downvote
Hi and thanks for the help. The counters are stable infact I have reset them and after one day the counters are 0. so I think there are not mismatch between interfaces and ports.

Regards

P4zz3o
 
Upvote 0 Downvote
Have you made any changes? Have you generated any traffic between the two problem nodes?

/

tim@tim-laptop ~ $ sudo apt-get install windows
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Couldn't find package windows...Thank Goodness!
 
Upvote 0 Downvote
Status
Not open for further replies.

Similar threads

Skip Rango
  • Locked
  • Question
how to backup cisco sg500-52p switch
Replies
1
Views
396
madwok
madwok
pbxcomm
  • Locked
  • Question
CISCO VG450
Replies
1
Views
415
nt8d09
nt8d09
Luzbel
  • Locked
  • Question
Connecting HVAC controller to network
Replies
0
Views
303
Luzbel
Luzbel
Jared R
  • Locked
  • Question
Cisco UC320W Paging Help
Replies
0
Views
409
Jared R
Jared R
Hayden09
  • Locked
  • Question
Cisco Sg-300 Flapping?
Replies
0
Views
366
Hayden09
Hayden09

Part and Inventory Search

Sponsor

Back
Top