[AG-TECH] Re: [AG-USERS] UAMS Access Grid

[Jacob Jenkins]

We recently had and solved a problem with the exact symptoms. The  
problem was related to our not advertising MBGP routes. We had some  
successful tests with sites in Mississippi but could not talk to people  
outside the state.
The problem was difficult because by default, Cisco routers translate  
BGP routes into MBGP routes and as long as you are talking  
Cisco-to-Cisco, there is no problem. Abilene, however, has a Juniper  
router where we tie into them which does not do this. Since the  
universities in Mississippi are tied into our own high speed network  
(which uses Cisco routers exclusively, I believe) and we conducted all  
of our preliminary testing with AG sites in Mississippi, we never  
noticed we had a problem.
So, make sure you are advertising MBGP routes. When we started doing  
this, it was like turning on a light switch, things just started  
working.

On Tuesday, May 27, 2003, at 12:17 PM, Jennifer Teig von Hoffman wrote:

> Sounds like a multicast problem to me too; a lot of us have  
> experienced one-way multicast outages at one time or another.
>
> NLANR's multicast beacon can be a big help in tracking down the source  
> of the multicast problem; there's detailed info about it at:
>
>    http://dast.nlanr.net/Projects/Beacon/
>
> - Jennifer
>
> Tom Coffin wrote:
>
>>
>>
>> Sounds like you have multicast problems with your network.
>>
>> First and foremost you need to engage your networking folks
>> into trouble shooting that problem.
>>
>> Secondarily, you could use the bridging infastructure still
>> supported by ANL by using vtc commands. Several of the
>> virtual venues offer vtc support - This will bridge your
>> sites into the multicast environment.
>>
>> A third method would be to create your own quickbridge.
>> Info for that can be found in the AGDP
>> http://www.accessgrid.org/agdp/
>> http://www.accessgrid.org/agdp/howto/quickbridge/1.2/html/ 
>> introduction.html
>>
>>
>> _____________________________________________________
>> At 11:25 AM 5/27/2003 -0500, Smith, Heather L wrote:
>> >>>>
>>
>>
>> Hi. I have a couple of requests from anyone who could help us.
>>
>>
>>
>>
>> We have a BIG meeting with University of New Mexico next Monday and  
>> we are having problems linking with them. We here at UAMS can see and  
>> hear UNM, but they cannot see our video or hear our audio, but we can  
>> communicate through the MUD and DPPT works with us as the master and  
>> UNM as the client. We had this problem a couple of weeks ago and  
>> tested with Argonne and University of Connecticut and things went off  
>> without a hitch. So here's what I need:
>>
>>
>>
>> * Does anybody have any suggestions as to why this problem is  
>> occurring?
>> * Is there anybody that can meet in the testing room or some other  
>> venue in order to test our Access Grid?
>>
>>
>>
>>
>> Thanks for your help!
>>
>> Heather Smith
>>
>> Curriculum Support Liaison
>>
>> University of Arkansas for Medical Sciences
>>
>> Library Learning Resource Center
>>
>> 4301 W. Markham, # 586
>>
>> Little Rock, Arkansas 72205
>>
>> Phone: 501-686-8116
>>
>> Email: smithheatherl at uams.edu
>>
>>
>>
>>
>> <<<<
>>
>>
>>
>>
>>
>>
>> ___________________________________________________________
>> Tom Coffin .......................... tcoffin at ncsa.uiuc.edu
>
>
>
>
>
Jacob Jenkins
Network Administrator/Access Grid Node Operator
Office of Research and Sponsored Programs
The University of Mississippi
(662) 915-7482