The authorized keys files on both machines are the same. So, I am unaware of any other thing to check ..
On the one that works (host A->B) I get ..
debug1: Authentications that can continue: publickey
debug1: Next authentication method: publickey
debug1: Offering DSA public key: foo.macbook.air
debug1: Server accepts key: pkalg ssh-dss blen 433
debug1: Authentication succeeded (publickey).
On the one that doesn't work (host B->A) I get :
debug1: Authentications that can continue: publickey
debug1: Next authentication method: publickey
debug1: Trying private key: /home/foo/.ssh/id_rsa
debug1: Trying private key: /home/foo/.ssh/id_dsa
The /etc/ssh/ssh_config
files are the same on both hosts. and my ~/.ssh/authorized_keys
is identical on both hosts, with permissions 600. ~/.ssh
also has permissions 600.
Is the problem potentially that public key is not being 'Offered' by host B for some reason? I am at a loss as everything works one way, but not the other, and I can't see any obvious differences between the two servers.