09-30-2003 05:21 AM - edited 03-02-2019 10:40 AM
Hi There,
We have a 2MB serial interface that is really busy and I was wondering what I could do to improve upon this config. I have included the config and a sh int s0/0 which happens to be the interface getting hammered. CPU proc is at 65% + continually and the process using the most CPU is IP @ 6.5%.
I was thinking of putting on WFQ as it should control traffic better than FIFO or am I wrong?
Any help would be hugely appreciated.
Thanks
Serial0/0 is up, line protocol is up
Hardware is PowerQUICC Serial
Description: IPclear Frame link 1
MTU 1500 bytes, BW 2048 Kbit, DLY 20000 usec,
reliability 255/255, txload 233/255, rxload 183/255
Encapsulation FRAME-RELAY IETF, loopback not set
Keepalive set (10 sec)
LMI enq sent 224, LMI stat recvd 224, LMI upd recvd 0, DTE LMI up
LMI enq recvd 0, LMI stat sent 0, LMI upd sent 0
LMI DLCI 0 LMI type is ANSI Annex D frame relay DTE
FR SVC disabled, LAPF state down
Broadcast queue 0/64, broadcasts sent/dropped 1124/0, interface broadcasts 112
4
Last input 00:00:00, output 00:00:00, output hang never
Last clearing of "show interface" counters 00:37:16
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 66304
Queueing strategy: fifo
Output queue: 22/40 (size/max)
5 minute input rate 1471000 bits/sec, 3372 packets/sec
5 minute output rate 1874000 bits/sec, 3480 packets/sec
7591762 packets input, 412670209 bytes, 0 no buffer
Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
7822955 packets output, 527987182 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets
0 output buffer failures, 0 output buffers swapped out
0 carrier transitions
DCD=up DSR=up DTR=up RTS=up CTS=up
version 12.2
service timestamps debug uptime
service timestamps log datetime
no service password-encryption
!
hostname "IPC1001"
!
logging buffered 8000 debugging
no logging console
enable password xxxx
!
clock summer-time BST recurring
ip subnet-zero
!
!
no ip domain-lookup
!
ip audit notify log
ip audit po max-events 100
!
call rsvp-sync
!
interface FastEthernet0/0
ip address 10.126.35.245 255.255.252.0
duplex auto
speed auto
!
interface Serial0/0
description IPclear Frame link 1
bandwidth 2048
no ip address
encapsulation frame-relay IETF
no fair-queue
frame-relay lmi-type ansi
!
interface Serial0/0.1 point-to-point
description 2Meg IP Clear Link
bandwidth 2048
ip unnumbered FastEthernet0/0
ip accounting output-packets
frame-relay class 2048k
frame-relay interface-dlci 101
!
interface FastEthernet0/1
no ip address
shutdown
duplex auto
speed auto
!
interface Serial0/1
no ip address
shutdown
!
router rip
version 2
redistribute bgp 64531
network 10.0.0.0
default-metric 3
no auto-summary
!
router bgp 64531
no synchronization
bgp log-neighbor-changes
redistribute connected
redistribute static
neighbor 10.126.35.250 remote-as 65400
neighbor 62.6.192.196 remote-as 2856
neighbor 62.6.192.196 ebgp-multihop 255
neighbor 62.6.192.196 update-source FastEthernet0/0
neighbor 62.6.192.196 filter-list 1 in
default-information originate
no auto-summary
!
no ip classless
ip route 0.0.0.0 0.0.0.0 Serial0/0.1
ip route 10.126.32.0 255.255.252.0 FastEthernet0/0
ip route 62.6.192.196 255.255.255.255 Serial0/0.1
ip http server
ip as-path access-list 1 deny _2856$
ip as-path access-list 1 permit .*
!
map-class frame-relay 2048k
no frame-relay adaptive-shaping
no logging trap
no cdp run
!
snmp-server community xxx
snmp-server community snmpv1 view xxxx RO
snmp-server trap-source FastEthernet0/0
snmp-server location xxxx
snmp-server chassis-id cisco2621
no snmp-server enable traps tty
snmp-server enable traps config
snmp-server enable traps entity
snmp-server enable traps envmon
snmp-server enable traps bgp
snmp-server enable traps frame-relay
snmp-server enable traps syslog
snmp-server enable traps rtr
snmp-server host xxxx snmpv1
!
dial-peer cor custom
!
line con 0
password xxxx
login
line aux 0
line vty 0 4
password xxxx
login
ntp clock-period 17180021
ntp server 10.126.35.248 source FastEthernet0/0
end
09-30-2003 06:41 AM
The output you provided indicates the reason for drops is the load on the link. The question is what do you want to do? Reduce the load or improve the chances for certain traffic to make it through? If you want to reduce the load then you will need to rate limit traffic toward that link (ie, at the ingress FE ints on the router). If you want to create a more fair utilization of the link (still dropping though) then WFQ or CBWFQ will help. Remember you have a 100Mb FE feeding a 2Mb Serial so your drops are expected.
09-30-2003 08:11 AM
You could tune rip to reduce its effects. Stretch out the updates and the interpacket delay.
Also, not sure but I'm wondering if the unnumbered interface causes any traffic from the ethernet to get on the circuit (layer 3 broadcasts, etc.) ? Anyone know if thats could be happenning???
09-30-2003 12:55 PM
You can enable CEF if the CPU utilisation is hitting high. Observe the type of traffic flowing through the router by enabling " ip route cache flow" on the ethernet. then issue "show ip cache flow" to check if ICMP traffic is high due to recent viruses.
10-01-2003 12:35 AM
Hi There,
Thanks for the help all, I will investigate these options.
Regards
Andrew Morris
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