05-17-2015 07:35 PM - edited 03-05-2019 06:55 AM
Hello,
I have a problem when i configure GRE tunnel over WAN (MPLS). I configure GRE tunnel between Cisco Catalist 4500 and SM-ES3G-16-P on ISR 3945. At first, there was not any problem at all. But, when traffic is increasing (Voice traffic), link becomes intermittent and CPU on SM-ES3G-16-P is high (68%). the highest cpu proccess is IP Input (>60%). Is there any suggestion for this problem? Thanks
4500 Configuration:
================
show run int tunnel
================
interface Tunnel14
bandwidth 1000000
ip address 172.29.1.6 255.255.255.252
ip mtu 1400
ip tcp adjust-mss 1360
delay 1
tunnel source GigabitEthernet2/3
tunnel destination 10.10.100.254
==============
show int tunnel
==============
Tunnel14 is up, line protocol is up
Hardware is Tunnel
Internet address is 172.29.1.6/30
MTU 17900 bytes, BW 1000000 Kbit/sec, DLY 10 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation TUNNEL, loopback not set
Keepalive not set
Tunnel source 172.16.21.194 (GigabitEthernet2/3), destination 10.10.100.254
Tunnel Subblocks:
src-track:
Tunnel14 source tracking subblock associated with GigabitEthernet2/3
Set of tunnels with source GigabitEthernet2/3, 1 member (includes iterators), on interface <OK>
Tunnel protocol/transport GRE/IP
Key disabled, sequencing disabled
Checksumming of packets disabled
Tunnel TTL 255, Fast tunneling enabled
Tunnel transport MTU 1476 bytes
Tunnel transmit bandwidth 8000 (kbps)
Tunnel receive bandwidth 8000 (kbps)
Last input 00:00:01, output 00:00:00, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 4
Queueing strategy: fifo
Output queue: 0/0 (size/max)
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 95000 bits/sec, 114 packets/sec
15504389 packets input, 7190678105 bytes, 0 no buffer
Received 0 broadcasts (0 IP multicasts)
0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
104453835 packets output, 14200412300 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets
0 unknown protocol drops
0 output buffer failures, 0 output buffers swapped out
SM-ES3G-16-P Configuration:
================
show run int tunnel
================
interface Tunnel14
bandwidth 1000000
ip address 172.29.1.5 255.255.255.252
ip mtu 1400
ip tcp adjust-mss 1360
delay 1
tunnel source 10.10.100.254
tunnel destination 172.16.21.194
end
==============
show int tunnel
==============
Tunnel14 is up, line protocol is up
Hardware is Tunnel
Internet address is 172.29.1.5/30
MTU 17916 bytes, BW 1000000 Kbit, DLY 10 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation TUNNEL, loopback not set
Keepalive not set
Tunnel source 10.10.100.254, destination 172.16.21.194
Tunnel protocol/transport GRE/IP
Key disabled, sequencing disabled
Checksumming of packets disabled
Tunnel TTL 255, Fast tunneling enabled
Tunnel transport MTU 1476 bytes
Last input 00:00:00, output 00:00:07, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 1997
Queueing strategy: fifo
Output queue: 0/0 (size/max)
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
99312017 packets input, 13601218040 bytes, 0 no buffer
Received 0 broadcasts (0 IP multicasts)
0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
15507171 packets output, 7194871509 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets
0 output buffer failures, 0 output buffers swapped out
05-17-2015 07:48 PM
What is the iOS?
05-17-2015 08:08 PM
Hi Charles,
4500 IOS version
-------------------------
Cisco IOS Software, IOS-XE Software, Catalyst 4500 L3 Switch Software (cat4500e-UNIVERSAL-M), Version 03.03.02.SG RELEASE SOFTWARE (fc1)
license: ipbase
SM-ES3G-16-P version
--------------------------------
Cisco IOS Software, C3560E Software (C3560E-UNIVERSALK9-M), Version 12.2(52)EX1, RELEASE SOFTWARE (fc1)
license: ipservices
05-17-2015 10:58 PM
There is an Ask the Expert: High CPU on IOS in the LAN, Switching and Routing section, perhaps a great opportunity for such a question!
As you know, one characteristic of voice traffic is that you have many very small packets. The router, in your case a software-based ISR, has to encapsulate every single packet (GRE- and new IP-header). Of course there are limitations, unfortunately it appears to be impossible to find any official recommendations on that.
So again, you may want to ask this question at the Ask-the-Expert event, I believe Vinit Jain could provide with some very valuable information.
HTH
Rolf
05-17-2015 11:38 PM
Hi Rolf,
Thank you for your advise, i am looking forward to join the Ask-the-Expert event.
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