common checks performed when passing on an IPv4 PA allocation from one end-customer to another

[m4rtntns at gmail.com (Martin T)]

Hi,

when one end-customer has been using for example /24 IPv4 allocation
for a while and returns this(for example changes an ISP) to LIR, then
are there some good practices before handing out this same /24 to a
new customer? I guess LIR should:

1) remove all the DNS PTR records, classless of classful delegations
2) check if some of the IP addresses are in DNSBL(maybe the previous
customer was a spammer). Example with 93.184.216.0/24:

$ for ip in {0..255}.216.184.93;\
> do for addr in \
> cbl.abuseat.org \
> dnsbl.inps.de \
> no-more-funn.moensted.dk \
> dnsbl.sorbs.net \
> bl.spamcannibal.org \
> bl.spamcop.net \
> psbl.surriel.com \
> dnsrbl.swinog.ch; \
> do dig @8.8.8.8 "$ip"."$addr" +short | grep -q "^127.0.0." && \
> echo "DNSBL-Alarm: $ip is listed on $addr"; done; done
$


Anything else?


regards,
Martin