Upgrade to 12.1

[Doug Hardie]

I tried to upgrade a 12.0 system to 12.1 tonight.  Freebsd-upgrade gave me:

Fetching metadata signature for RELEASE-12.1 from update4.freebsd.org... failed.
Fetching metadata signature for RELEASE-12.1 from update2.freebsd.org... failed.
Fetching metadata signature for RELEASE-12.1 from update1.freebsd.org... failed.
No mirrors remaining, giving up.

This happened several times tonight.  Any ideas what is going on?

-- Doug