Why am I suddenly unable to ping or curl a floating IP server from itself?

I have configured a floating IP to point at my server.

When I do: ping <my-floating-ip-address>

It works fine from my computer and from other servers. But when I run the same command from the server itself (i.e. the server currently pointed to by the floating IP), it produces no results.

Uptil yesterday I was able to do a curl from my server to itself via the floating IP. Today I can’t. I haven’t changed any configuration on my side.

Has something changed in the way floating IP addresses work?

I’ll include my firewall settings for completeness, but I haven’t changed them recently and, as I say, it used to work.

Chain INPUT (policy DROP)
target     prot opt source               destination
ACCEPT     all  --  anywhere             anywhere
ACCEPT     all  --  anywhere             anywhere             state RELATED,ESTABLISHED
ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:http state NEW
ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:https state NEW
ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:ssh state NEW
ACCEPT     icmp --  anywhere             anywhere             limit: avg 1/sec burst 5 icmp echo-request

Chain FORWARD (policy DROP)
target     prot opt source               destination

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination