Small cisco boxes doing IPv6?

Eric Vyncke (evyncke) evyncke at cisco.com
Tue Feb 14 15:30:28 CET 2012


Michael

Does your mix include full size packets? Then, those packets are dropped by the router and an ICMP is generated. You may want to set the MTU of the Ethernet link to 1492 as well (assuming that RA will advertize this MTU size).

Does the destination exist? You may be receiving 'backscatter' traffic for IPv6 which would divide throughput by two of course

Else, nothing glaring

> -----Original Message-----
> From: ipv6-ops-bounces+evyncke=cisco.com at lists.cluenet.de [mailto:ipv6-ops-
> bounces+evyncke=cisco.com at lists.cluenet.de] On Behalf Of Michael Adams
> Sent: mardi 14 février 2012 11:54
> To: ipv6-ops at lists.cluenet.de
> Subject: Re: Small cisco boxes doing IPv6?
> 
> 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


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