Small cisco boxes doing IPv6?

[Marc Binderberger]

Hello Michael,

> Hints welcome.

you have "ipv6 verify unicast reverse-path" configured but not the equivalent for IPv4. Now the reverse-path lookup doubles the CEF lookup which could in worst case double your CPU utilization.

Would be interesting to see how numbers for IPv4 look like with unicast reverse verification enabled.


Regards, Marc



On 2012-02-14, at 11:53 , Michael Adams wrote:

> Am 13.02.2012 11:36, schrieb Marco Hogewoning:
>> If it is of any help, we now have two models running 2921 and 1921 and both the systems were delivered on 15.1(4)M3, which is from december 2011,  IPbase and K9 license on the box. I ran a couple of quick tests and confirmed IPv6 functionality on BGP, OSPF and IS-IS. These were no performance tests, but at least I verified the process starts and is capable of exchanging a static IPv6 route. Little disclaimer: this was the first time I ever touched IS-IS, your mileage may vary.
> 
> I did some performance tests on a 1921 with 15.1(2)T4 / security license and
> experienced a serious degradation when using PPPoE uplinks.
> 
> v6
> unidirectional IMIX UDP packets, G0/0 -> G0/1 : 100 Mbit/s @ 20 % CPU
> unidirectional IMIX UDP packets, G0/0 -> G0/1 (PPPoE): 50 Mbit/s @ 72 % CPU
> 
> v4
> unidirectional IMIX UDP packets, G0/0 -> G0/1 : 100 Mbit/s @ 14 % CPU
> unidirectional IMIX UDP packets, G0/0 -> G0/1 (PPPoE): 100 Mbit/s @ 26 % CPU
> 
> For me it looks like the box has some problems with IPv6 together with PPP. It may also
> be a configration issue. So here is a part of the config. The box was not doing NAT or
> ipv6 inspect.
> 
> no ipv6 source-route
> ipv6 unicast-routing
> ipv6 cef
> no ip source-route
> ip cef
> !
> interface GigabitEthernet0/0
> description traffic generator
> ip address x.x.x.x 255.255.255.0
> no ip redirects
> load-interval 30
> duplex auto
> speed auto
> ipv6 address 2001:db8::1/64
> ipv6 enable
> no ipv6 redirects
> ipv6 verify unicast reverse-path
> !
> interface GigabitEthernet0/1
> description Uplink
> no ip address
> load-interval 30
> duplex auto
> speed auto
> pppoe enable group global
> pppoe-client dial-pool-number 1
> no cdp enable
> !
> interface Dialer1
> mtu 1492
> ip address negotiated
> encapsulation ppp
> dialer pool 1
> dialer-group 1
> ipv6 address FE80::CE link-local
> ipv6 address autoconfig
> ipv6 enable
> ppp authentication pap callin
> ppp pap sent-username <its-me> password <its-really-me>
> no cdp enable
> !
> ipv6 route ::/0 Dialer1
> ip route 0.0.0.0 0.0.0.0 Dialer1
> 
> 
> Hints welcome.
> 
> Michael
> 

--
Marc Binderberger           <marc at sniff.de>