Timeout errors downloading channel repodata on clients of Red Hat Proxy servers

Issue

• error during "yum update" when downloading filelists.xml.gz:

Error: failed to retrieve repodata/c45362b1906d65e7dbf7c55772c21462ea3cd4a6-filelists.xml.gz from rhel-x86_64-server-5
error was [Errno 12] Timeout: <urlopen error >
You could try using --skip-broken to work around the problem
You could try running: package-cleanup --problems
                        package-cleanup --dupes
                        rpm -Va --nofiles --nodigest
The program package-cleanup is found in the yum-utils package.

• error when updating clients that are getting updates via Proxy from Satellite:

Error: failed to retrieve repodata/filelists.xml.gz from rhel-x86_64-server-6
error was [Errno 12] Timeout on https://server.example.com/XMLRPC/GET-REQ/rhel-x86_64-server-6/repodata/filelists.xml.gz: (28, 'Operation too slow. Less than 1 bytes/sec transfered the last 60 seconds')