I've noticed this in CentOS 4 & 5 and Fedora 5 & 6. If I'm in Gnome desktop and using any of the terminal programs and I ssh into any server, the connection just hangs. Not drops, it just hangs and doesn't recover. These servers are all over the country on different ISPs in Tier1 datacenters. Some are in our office, so they are on the local lan. We have a mix of RHEL 3, 4 & 5 and CentOS 4 & 5 on the servers. If I'm using a windows computer with putty or SecureCRT this never happens, it only happens when I'm using any of our linux desktops or laptops. It doesn't matter if I'm in the office or at home (on comcast) or over at a friend's house (verizon dsl). This problem has been going on for at least two years and I'm finally fed up to the point where I might switch back to windows since 99% of my job is working while ssh'ed into servers. Anyone had similar problems? -matt
I should add that the hang occurs after an unknown amount of time. -matt On 7/12/07, Matt Shields <mattboston at gmail.com> wrote:> I've noticed this in CentOS 4 & 5 and Fedora 5 & 6. If I'm in Gnome > desktop and using any of the terminal programs and I ssh into any > server, the connection just hangs. Not drops, it just hangs and > doesn't recover. > > These servers are all over the country on different ISPs in Tier1 > datacenters. Some are in our office, so they are on the local lan. > We have a mix of RHEL 3, 4 & 5 and CentOS 4 & 5 on the servers. If > I'm using a windows computer with putty or SecureCRT this never > happens, it only happens when I'm using any of our linux desktops or > laptops. It doesn't matter if I'm in the office or at home (on > comcast) or over at a friend's house (verizon dsl). This problem has > been going on for at least two years and I'm finally fed up to the > point where I might switch back to windows since 99% of my job is > working while ssh'ed into servers. > > Anyone had similar problems? > > -matt >
On Thu, Jul 12, 2007 at 09:46:00AM -0400, Matt Shields wrote:> I've noticed this in CentOS 4 & 5 and Fedora 5 & 6. If I'm in Gnome > desktop and using any of the terminal programs and I ssh into any > server, the connection just hangs. Not drops, it just hangs and > doesn't recover. >ssh -vvv might give a glue selinux enforced on your client machines? Tru -- Tru Huynh (CentOS-3 i386/x86_64 Package Maintenance) http://pgp.mit.edu:11371/pks/lookup?op=get&search=0xBEFA581B -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 189 bytes Desc: not available URL: <http://lists.centos.org/pipermail/centos/attachments/20070712/0f31e7d5/attachment.sig>
selinux is turned off on both servers and desktops On 7/12/07, Tru Huynh <tru at centos.org> wrote:> On Thu, Jul 12, 2007 at 09:46:00AM -0400, Matt Shields wrote: > > I've noticed this in CentOS 4 & 5 and Fedora 5 & 6. If I'm in Gnome > > desktop and using any of the terminal programs and I ssh into any > > server, the connection just hangs. Not drops, it just hangs and > > doesn't recover. > > > > ssh -vvv might give a glue > selinux enforced on your client machines? > > Tru > -- > Tru Huynh (CentOS-3 i386/x86_64 Package Maintenance) > http://pgp.mit.edu:11371/pks/lookup?op=get&search=0xBEFA581B > > _______________________________________________ > CentOS mailing list > CentOS at centos.org > http://lists.centos.org/mailman/listinfo/centos > > >
I've seen a similar issue when I've had an ssh connection open to a remote site over a VPN connection (not a VPN client on my PC, but a VPN connection between my site and the remote site, between Cisco routers). Catting a large file would hang the connection, and I had to kill and re-establish the connection. The issue was that the maximum packet size over the VPN link was something like 1460. The VPN connection added 40 extra bytes of payload. When I would cat a large file, my computer would send 1500 byte packets with the do-not- fragment bit set. The routers couldn't pass the 1500 byte packet because it was too large, and the do-not-fragment bit prevented them from fragmenting the packet, so it would get dropped, and my connection would die. I don't remember the exact details, as it occurred a couple years ago, but the gist was that the MTU on the servers I had to connect to had to be reduced to something like 1460. I don't think this is exactly your situation, but it's just an idea of something to consider. -Tim On Jul 12, 2007, at 9:46 AM, Matt Shields wrote:> I've noticed this in CentOS 4 & 5 and Fedora 5 & 6. If I'm in Gnome > desktop and using any of the terminal programs and I ssh into any > server, the connection just hangs. Not drops, it just hangs and > doesn't recover. > > These servers are all over the country on different ISPs in Tier1 > datacenters. Some are in our office, so they are on the local lan. > We have a mix of RHEL 3, 4 & 5 and CentOS 4 & 5 on the servers. If > I'm using a windows computer with putty or SecureCRT this never > happens, it only happens when I'm using any of our linux desktops or > laptops. It doesn't matter if I'm in the office or at home (on > comcast) or over at a friend's house (verizon dsl). This problem has > been going on for at least two years and I'm finally fed up to the > point where I might switch back to windows since 99% of my job is > working while ssh'ed into servers. > > Anyone had similar problems? > > -matt > _______________________________________________ > CentOS mailing list > CentOS at centos.org > http://lists.centos.org/mailman/listinfo/centos