A nice copy and paste-able list of active Pingdom monitoring nodes is available here: https://apps.codinglog.com/pingdom/active_probes/
It uses the Pingdom API so is always up to date. For some reason Pingdom’s own list is styled (form over factor) so it’s a nightmare to drop straight in to your firewall allow list. I dumped this straight in to CSF (ConfigServer Security & Firewall) and it worked a treat.
I’m afraid that site is no longer available. I use the Pingdom RSS-feed, with some bash-scripting to format the output for various applications. For example (hoping the formatting won’t be mangled):
Apache ACL:
printf "# Pingdom servers at %s\nAllow from " "$(date +%Y-%m-%d' '%H.%M.%S)" ; \
wget -qO- https://my.pingdom.com/probes/feed \
| awk '/IP: / {print $2}' | awk -F';' '{print$1}' | sort -n \
| while read ip; do \
printf "%s " "$ip" ;
done | sed 's/ $//' ; echo
Varnish ACL:
printf "# Pingdom servers at %s\n" "$(date +%Y-%m-%d' '%H.%M.%S)" ; \
echo "acl monitoring {"; \
wget -qO- https://www.pingdom.com/rss/probe_servers.xml \
| grep 'IP: ' \
| perl -p -e 's,.*IP: (.*); Host.*, "$1";,' \
| sort -n; \
echo "}"
Hmm, your blog pretty-prints the quotation marks, breaking the script. I’ve posted the code on https://gist.github.com/Yggdrasil/163d63a11f0efbc6a13b.
I’ve wrapped the comment in code tags as well. Thanks for this!