Sign of Network congestion

Lost & Found · ‎06-01-2015

Hi,

I Would like to ask how to troubleshoot this scenario.

R1 and R2 act as a Default Gateway

I have 2 site A & B

R1 of Site A is connected to R2 of Site B via Leased line the problem is:

1. From R1 Site A I can't ping the R2 and Firewall

2. From Site A workstation I can ping all the servers, devices and workstation vise versa.

3. From Site A our trunkline is connected to Site B so in order to access it the packet will go to site B via leased line.

So from Site A we have no connection to trunk line but when I restart the Site A R1 it works all connection was restored.

It always happen in our side but when I reload the R1 it's working.

Note: R1 and R2 Show IP INT BRIEF result is all up.

Q: What is the main reason of this?

What is the solution or how to troubleshoot this?

Is this the sign that i need to replace my Router?

How to check the memory or process or the load is it over?

How to determine Congestion?

Please see the attached photo.

- See more at: https://supportforums.cisco.com/discussion/12519316/sign-router-link-congestion#sthash.WUMuq9WP.dpuf

Mark Malone · ‎06-02-2015

Hi could be a few things could cause this need to narrow it down

Can you post the show logging from each router when the issue occurs before you reboot R1 ?

Also post show interface outputs of the two trunk interfaces and the show run int for each interface

Take a show proc cpu sorted as well and show memory

Lost & Found · ‎06-02-2015

Hi,

Upon checking the trunk interfaces there's no display

same as show logging I'm using free syslog server.

On R2 =

2015-05-26 23:48:28 Local7.Notice 10.34.31.253 69: *May 26 18:26:37.105: %OSPF-5-ADJCHG: Process 1, Nbr 121.96.63.179 on Port-channel1 from FULL to DOWN, Neighbor Down: Dead timer expired

2015-05-26 23:49:47 Local7.Notice 10.34.31.253 70: *May 26 18:27:55.525: %OSPF-5-ADJCHG: Process 1, Nbr 121.96.63.179 on Port-channel1 from LOADING to FULL, Loading Done

but this 121.96.63.179 is a sub interface only where not using this one.

please see the attached file for how proc cpu sorted as well and show memory

thanks

Mark Malone · ‎06-02-2015

Hi

cpu and memory is fine , is there a reason the pos set to half-duplex its causing a lot of collisions each side of the link , as well im seeing bandwidth adjustments on 1 side have you changed default values whats the running config on the port-channel member interfaces

260527 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog
     0 input packets with dribble condition detected
     281756126 packets output, 969343862 bytes, 0 underruns
     228706 output errors, 280053 collisions,

Lost & Found · ‎06-02-2015

Hi,

How can I verify whether my Memory and CPU are working properly based on my post ?

R1=
Port-channel1 is up, line protocol is up
Hardware is FEChannel, address is c84c.75c1.6086 (bia 0017.5904.c4f8)
Internet address is 10.47.250.78/20
MTU 1500 bytes, BW 200000 Kbit/sec, DLY 100 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
ARP type: ARPA, ARP Timeout 04:00:00
No. of active members in this channel: 2
Member 0 : FastEthernet0/3/0 , Half-duplex, 100Mb/s
Member 1 : FastEthernet0/0/0 , Half-duplex, 100Mb/s
interface Port-channel1
ip address 10.47.250.78 255.255.240.0
hold-queue 150 in

R2=
Port-channel1 is up, line protocol is up
Hardware is FEChannel, address is 0007.7d5f.00a0 (bia 0016.c7be.aec0)
Internet address is 10.47.250.77/20
MTU 1500 bytes, BW 110000 Kbit/sec, DLY 100 usec,
ARP type: ARPA, ARP Timeout 04:00:00
No. of active members in this channel: 2
Member 0 : FastEthernet0/1/0 , Half-duplex, 100Mb/s
Member 1 : FastEthernet0/0/0 , Half-duplex, 100Mb/s

interface Port-channel1
ip address 10.47.250.77 255.255.240.0
hold-queue 150 in

How to know who's causing the collision on my port-channel?

thanks

Lost & Found · ‎06-03-2015

Kindly check this command I think it's connected to port channel?

R1=
interface FastEthernet0/0/0
no ip address
duplex half
speed auto
channel-group 1
R1#sh interfaces f0/0/0
FastEthernet0/0/0 is up, line protocol is up
Hardware is FastEthernet, address is c84c.75c1.6086 (bia c84c.75c1.6086)
MTU 1500 bytes, BW 100000 Kbit/sec, DLY 100 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Half-duplex, 100Mb/s, 100BaseTX/FX
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:16, output 00:00:00, output hang never
Last clearing of "show interface" counters 00:08:21
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 9000 bits/sec, 9 packets/sec
5 minute output rate 33000 bits/sec, 17 packets/sec
4016 packets input, 848894 bytes
Received 98 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog
0 input packets with dribble condition detected
8029 packets output, 1715966 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets
0 unknown protocol drops
0 babbles, 0 late collision, 1 deferred
0 lost carrier, 0 no carrier
0 output buffer failures, 0 output buffers swapped out
!
interface FastEthernet0/3/0
no ip address
duplex half
speed auto
channel-group 1
FastEthernet0/3/0 is up, line protocol is up
Hardware is FastEthernet, address is c84c.75c1.6086 (bia 0007.7d00.21e9)
MTU 1500 bytes, BW 100000 Kbit/sec, DLY 100 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Half-duplex, 100Mb/s, 100BaseTX/FX
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:55, output 00:00:00, output hang never
Last clearing of "show interface" counters 00:08:48
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 50000 bits/sec, 18 packets/sec
5 minute output rate 18000 bits/sec, 6 packets/sec
12029 packets input, 5824195 bytes
Received 101 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog
0 input packets with dribble condition detected
3942 packets output, 1481612 bytes, 0 underruns
12 output errors, 14 collisions, 0 interface resets
0 unknown protocol drops
0 babbles, 5 late collision, 1 deferred
0 lost carrier, 0 no carrier
0 output buffer failures, 0 output buffers swapped out
!

R2=
interface FastEthernet0/0/0
description To R1
no ip address
duplex half
speed auto
channel-group 1
!
R2#sh interface f0/0/0
FastEthernet0/0/0 is up, line protocol is up
Hardware is FastEthernet, address is 0007.7d5f.00a0 (bia 0007.7d5f.00a0)
Description: To Laguna Plant Site
MTU 1500 bytes, BW 100000 Kbit/sec, DLY 100 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Half-duplex, 100Mb/s, 100BaseTX/FX
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:58, output 00:00:00, output hang never
Last clearing of "show interface" counters 8w3d
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 24000 bits/sec, 20 packets/sec
5 minute output rate 7000 bits/sec, 8 packets/sec
104916266 packets input, 163194647 bytes
Received 986782 broadcasts, 0 runts, 0 giants, 0 throttles
69082 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog
0 input packets with dribble condition detected
93210976 packets output, 2187548831 bytes, 0 underruns
60367 output errors, 134651 collisions, 0 interface resets
0 unknown protocol drops
0 babbles, 0 late collision, 144988 deferred
4 lost carrier, 0 no carrier
0 output buffer failures, 0 output buffers swapped out

interface FastEthernet0/1/0
no ip address
duplex half
speed auto
channel-group 1

R2#sh interface f0/1/0
FastEthernet0/1/0 is up, line protocol is up
Hardware is FastEthernet, address is 0007.7d5f.00a0 (bia d0d0.fd30.c30a)
MTU 1500 bytes, BW 100000 Kbit/sec, DLY 100 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Half-duplex, 100Mb/s, 100BaseTX/FX
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:15, output 00:00:00, output hang never
Last clearing of "show interface" counters 8w3d
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 4000 bits/sec, 3 packets/sec
5 minute output rate 51000 bits/sec, 38 packets/sec
171273763 packets input, 4267465497 bytes
Received 986784 broadcasts, 0 runts, 0 giants, 0 throttles
190781 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog
0 input packets with dribble condition detected
188603480 packets output, 1811106222 bytes, 0 underruns
167752 output errors, 372793 collisions, 0 interface resets
0 unknown protocol drops
0 babbles, 0 late collision, 378544 deferred
6 lost carrier, 0 no carrier
0 output buffer failures, 0 output buffers swapped out

based on the commands I would like to ask what is the purpose on the interface f0/0/0 etc. but it has no Ip address configured but it has channel group?

no ip address
channel-group 1

Tried to run test I enter the command shutdown in interface f0/0/0 of R1 the result I cant ping r2. DOWN. IP phone cant connect to R2 site also.

and interface FastEthernet0/3/0 enter the command shutdown I can ping the R2. Still UP.

thanks in advance

Mark Malone · ‎06-03-2015

Hi your cpu is only running at 4 and 15% for both switches over 5 minute period on the posts you attached and your memory i ran through Cisco website theres a tool output interpretor can confirm the percent easily its fine , the issue is those collisions, the channel-group without an ip is just a layer 2 port-channel switched

to stop the collisions and errors hard set all the member interfaces to be duplex-full and speed 100 , this is the 4 fasthethernet interfaces which are part of the etherchannel on each switch , interfaces should not be set to half unless specifically required

Member 0 : FastEthernet0/1/0 , Half-duplex, 100Mb/s
Member 1 : FastEthernet0/0/0 , Half-duplex, 100Mb/s

Member 0 : FastEthernet0/3/0 , Half-duplex, 100Mb/s
Member 1 : FastEthernet0/0/0 , Half-duplex, 100Mb/s

Lost & Found · ‎06-03-2015

Hi,

R1 = Connected to ISP Device (leased Line)

FastEthernet0/1/0
FastEthernet0/0/0

R2 = Connected to ISP Device (leased Line)

FastEthernet0/3/0
FastEthernet0/0/0

Please see the attached file

thanks

Mark Malone · ‎06-03-2015

Check with whoever owns that line , are your interfaces supposed to be half-duplex settings the ISP usually states this when providing a new line and your connecting to their equipment ? Usually they would be hard set speed 100 duplex-full on your side on each of those fastethernet interfaces ,your interfaces are being hammered with errors due to this , once you set your side as half-duplex or lkeave it as default half your going to see errors which will effect your traffic as theres constantly collisions incrementing thousands in just 8 weeks input and output

Lost & Found · ‎06-03-2015

Hi,

so are you saying that the best solution for this is to run with full duplex?

I'll inquire to our ISP about that.

thanks

Mark Malone · ‎06-04-2015

Yes running full-duplex will prevent those errors and collisions that are constantly going up , you need to resolve them before looking at anything else regarding congestion as errors like that can cause retransmissions which has an effect on traffic between routers

Lost & Found · ‎06-04-2015

Hi,

It happened again we experience the same issue. but to they i havent restart any devices. after a few minutes network was restored.

does collision can affect our network?

thanks

Mark Malone · ‎06-04-2015

Yes they do every collisions causes retransmits

Lost & Found · ‎06-18-2015

Hi,

question: Since we configured this for a long time, working fine and this problem or link error is new. what is the main reason causing a lot of collision all though we know that we are running half duplex only?

Is that because we added some server and workstation?

what is the best way to explain this and how can i know whos causing lot of collision on our network??

thanks