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IOS SLB Loab Balance Questions

Forgive me if this is the wrong forum but it was the closest one I found relating to my issue.

I've trying to load balance four of our radius servers using IOS SLB. The config works well and the radius servers are accepting requests fine. I follow this article which wasn't too bad to follow:

http://www.cisco.com/application/pdf/en/us/guest/netsol/ns377/c649/cdccont_0900aecd800eb95f.pdf

My two questions are:

1. Sticky Option

I understand it's used to make sure the client's accounting information

goes to the correct real server, but I'm not sure how it really works

and what's the best time to set it to.

Eg:

ip slb vserver RAD-UDP-1646

virtual 210.x.x.224 udp 1646

serverfarm RADFARM

sticky 86400 group 10

inservice

a/ The documentation says "This configuraion causes the sticky database to store its entries for 86,400 seconds of inactivity". What do they mean by "inactivity" - no radius packets coming through? inactivity from the user's end?

b/ It also says "the client's IP address is added to the IOS SLB database..." - is this the client's framed IP that the ISP assigns to the customer???

c/ And what would be the optimum time to set the sticky timer to be?

2. SLB connection statistics

core1-router#sh ip slb reals

real farm name weight state conns

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

203.x.x.74 RADFARM 8 OPERATIONAL 0

203.x.x.78 RADFARM 8 OPERATIONAL 0

203.x.x.79 RADFARM 8 OPERATIONAL 0

203.x.x.80 RADFARM 8 OPERATIONAL 2

When you disconnect, the slb stats still show you as being connected to

the real server (and both udp ports) which isn't very accurate. There is a default "delay" time which handles TCP disconnections and after being disconnected for 10 sec, the SLB stats are updated to reflect this (I've verified this works)- but nothing about how it handles UDP disconnections??? This

would skew the stats and give us a very bad misrepresentation of the

number of current and valid connections. Is there anyway to correct this???

Thanks.

Andy

1 REPLY
Silver

Re: IOS SLB Loab Balance Questions

Inactivity for IOS SLB means that after specified time of inactivity, the client will be free to be load balanced to another server. As long as they remain active without an idle time , they will remain connected to the same real server. For the client's IP address which is added to the IOS SLB database I think it is the frammed IP address which the ISP assigns. The optimum time for the sticky timer will be its default value or say 60 seconds.

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