[git]ssh: Could not resolve hostname github.com: nodename nor servname provided, or not known

ssh: Could not resolve hostname github.com: nodename nor servname provided, or not known

This sounds like a DNS issue. Try switching to another DNS server and see if it works.

OpenDNS

    208.67.222.222
    208.67.220.220

GoogleDNS

    8.8.8.8
    8.8.4.4