Catalyst 3750G drops packets with IPv4 options

Hello,

I have a problem with a Cisco Catalyst 3750G switch/router.

In my tests, I could not get the 3750G to reliably route more than 3400 IPv4 packets per second when these packets contained IP options.

The packets were UDP/IPv4. I tried both small (payload = 100 bytes) and large (payload = 1450 bytes) packets.

The IP options consisted of 4 or 8 NOPs (option type 1). Thus there were no alignment issues, and nothing extra for the router to process.

3570 pps && payload= 100 : 1.1% packet loss 3570 pps && payload=1450 : 2.3% packet loss 5000 pps && payload=1450 : 30.2% packet loss

The following page does not mention my situation:

I ran show process cpu:

CPU utilization for five seconds: 87%/29%; one min: 89%; five min: 73% PID Runtime(ms) Invoked uSecs 5Sec 1Min 5Min TTY Process [...] 150 7678123 5843620 1313 54.63% 53.74% 43.74% 0 IP Input

A few entries show less than 0.15% CPU usage. All other show 0%.

Where does the 87% figure come from?

Is it 87% overall with 29% IRQ servicing => 58% other than IRQ.

Why is the router dropping packets if the CPU is not maxed out?

Is this a known problem?

Has it perhaps been fixed in a more recent firmware revision?

For reference: >show version Cisco IOS Software, C3750 Software (C3750-IPSERVICES-M), Version

12.2(25)SEC, RELEASE SOFTWARE (fc2) Copyright (c) 1986-2005 by Cisco Systems, Inc. Compiled Thu 14-Jul-05 21:33 by antonino

ROM: Bootstrap program is C3750 boot loader BOOTLDR: C3750 Boot Loader (C3750-HBOOT-M) Version 12.2(25r)SE, RELEASE SOFTWARE (fc)

cyrus uptime is 1 week, 2 days, 18 hours, 44 minutes System returned to ROM by power-on System image file is "flash:/c3750-ipservices-mz.122-25.SEC.bin"

cisco WS-C3750G-24TS-1U (PowerPC405) processor (revision A0) with

118784K/12280K bytes of memory. Processor board ID FOC0902U0GY Last reset from power-on 17 Virtual Ethernet interfaces 28 Gigabit Ethernet interfaces The password-recovery mechanism is enabled.

512K bytes of flash-simulated non-volatile configuration memory. Base ethernet MAC Address : 00:13:19:86:CA:00 Motherboard assembly number : 73-9637-07 Power supply part number : 341-0098-01 Motherboard serial number : FOC09020A2U Power supply serial number : DCA084701XH Model revision number : A0 Motherboard revision number : A0 Model number : WS-C3750G-24TS-S1U System serial number : FOC0902U0GY SFP Module assembly part number : 73-7757-02 SFP Module revision Number : A0 SFP Module serial number : CAT085207B5 Top Assembly Part Number : 800-25730-01 Top Assembly Revision Number : A0 Version ID : 01 CLEI Code Number : CNMWS00ARA Hardware Board Revision Number : 0x05

Switch Ports Model SW Version SW Image

------ ----- ----- ---------- ----------

• 1 28 WS-C3750G-24TS-1U 12.2(25)SEC C3750-IPSERVICES-M

Configuration register is 0xF

Regards.

read more and respond »

Posted 5 years ago by Spoon in Cisco Systems

Report misuse