Re: L2 behavior?!

can you upload a visio somewhere so we can have a look?

On 28/12/2010 23:43, Ivan Hrvatska wrote:
> I figured it out. The problem is in fact that arp timeout is 4 hours and mac
> aging time is 6 minutes on 6k switches. Doesn't have anything to do with
> asa. Two 6k switches are connected with two wan routers with 4 p2p L3 links
> and between them is ospf. So, when first packet comes from wan cloud 6k1
> looks at routing table and sees that destination host is on directly
> connected network. It sends arp and it gets respons that host is in vlanif
> 514. Mac table also learns that host's mac is in interface between 6k1 and
> 6k2. Since 6k2 has p2p L3 link with primary Wan router, packet from S to H
> never goes back to 6k1. After 6 min 6k1 removes entry from mac table but arp
> entry remains. When next packet from H to S comes to 6k1, it doesn't know on
> which port to send frame, so it floods on all ports in vlan 514.
> So, now I'm considering option to have only 6k1 as active hsrp gw and root
> bridge for all vlans. Right now I have half vlans active on 6k1 and other
> half on 6k2. Also, to configure arp timeout 2 hours and mac aging little bit
> less than 2 hours. Also, on p2p L3 links between 6k and wan routers to
> configure cost so that traffic takes only one path. It seems littlr bit hard
> to follow flow of the traffic with ospf load balancing and load balancing at
> layer 2.
> What do you think?
>
> On Dec 28, 2010 9:58 PM, "Vijay Shekhar"<v.shekhar_at_globalassurance.net>
> wrote:
>> I am a bit confused by your statement. May be its just me.
>>
>> You mentioned that 6k1 - 6k2 and 2960 are in L2 domain, and you also
>> mention that 6k2 should do interval Routing. There are contradictory.
>>
>> If 6k2 is indeed doing interval routing then 6k1 will see the MAC
>> address of 6k2 SVI to reach "s".
>>
>> It would perhaps he helpful if you can list out the VLAN #'s SVI IPs
>> and S& H IPs.
>>
>> Cheers!
>>
>> -Vijay Shekhar
>> CCIE(sec)#17589/CISSP/RHCE.
>> http://au.linkedin.com/in/vshekhar
>>
>>
>> Quoting Ivan Hrvatska<ivanzghr_at_gmail.com>:
>>
>>> Hi,
>>>
>>> I have scenario like this:
>>>
>>> H---Asa----6k1-----6k2
>>> ! !
>>> ! !
>>> 2960sw
>>> !
>>> S
>>>
>>> H-host in cloud (172.30.4.5), somewhere in distance network.y
>>> Asa-running in transparent mode
>>> Between 6k switches and 2960 is l2 domain (trunks).
>>> 6k switches running hsrp and 6k2 is active gw for vlans 500 and 514. It
> is
>>> also root bridge for those vlans. Asa has one IP in vlan 500.
>>> S is in vlan 514.
>>> Problem is that 6k1 never learns mac address of S. When traffic comes
> from H
>>> 6k1 floods network with packets that should go to S. Only time when 6k1
>>> learns S mac address is when you ping S from 6k1. After 480 sec is aging
>>> time and mac address is cleared. As I understand 6k1 should forward
> packets
>>> which has S as destanation to 6k2 as it is active gw for vlan 500 and
> then
>>> 6k2 should perform intervlan routing. Why flooding happens? Could asa
> make
>>> some problems cause of transparent mode?
>>>
>>> Regards
>>>
>>>
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Received on Tue Dec 28 2010 - 23:56:10 ART