Forum Discussion
2funky_105078
Cirrus
CirrusGTM iRule to set different TTL for each RR
Hi,
In our GTMs, I have the requirement to set manually the TTL timeout for a wide-IP,let's call it www.example.com (it is within our enterprise not in the internet), based on RTT and static met...
2funky_105078Cirrus
CirrusThis is the example i found in the wiki. But it doesnt cover the situation of DNS::answer == "use the RTT method" function.
when DNS_RESPONSE {
set rrs [DNS::answer]
foreach rr $rrs {
DNS::ttl $rr 60
}
}
Mohamed_Lrhazi
Altocumulus
AltocumulusYou need to inspect the DNS answer records, and make decisions about the TTL to set, based on the IP addresses in those DNS answers, right?
In the sample iRule you post, you see how you can access the list of RRs in the answer, and how to loop tru them, right? you get one RR in a variable named $rr, then you can dissect that record like so:
[DNS::name $rr]
[DNS::ttl $rr]
[DNS::class $rr]
[DNS::type $rr]
[DNS::rdata $rr]
I guess the record type needs to be "A", then the rdata would be a list of IP addresses? I would right the iRule to just log all those fields and learn how to parse it out from there....
