tylerdoman Posted October 21, 2006 Report Share Posted October 21, 2006 I using the trial version of Restrospect Multi-Server 7.5 for Windows and I'm trying to remotely backup a client machine over two dsl connections. I haven't been able to complete the first full backup of about 2gigs. I've tried twice and it failed both times with the following error: "Trouble reading files, error -519 (network communication failed)" It's weird cause it will start to backup and will go for a long time but fails in random places everytime. Nothing seems to be wrong on the client machine. So I don't have any clue why it's not working. Any ideas? Quote Link to comment Share on other sites More sharing options...
nekr0phage Posted October 23, 2006 Report Share Posted October 23, 2006 Hi, Retrospect wasn't designed to work over the internet. If you're going to be backing up from remote locations you should set up a VPN first. Quote Link to comment Share on other sites More sharing options...
redlex Posted August 23, 2007 Report Share Posted August 23, 2007 Hi there I'm also having -519 errors ('network communication failed'), and am backing up over the internet. I'm surprised to read that "Retrospect isn't designed to work over the internet". What is the difference between a VPN connection and a direct internet connection to a retrospect client? Both have IP addresses. Both use TCP/IP. What is the essential difference here? Quote Link to comment Share on other sites More sharing options...
rhwalker Posted August 23, 2007 Report Share Posted August 23, 2007 Quote: What is the essential difference here? Error recovery routines, MTU, etc. Quote: Both use TCP/IP. Um, only if the program opens a TCP connection. If a UDP connection is opened, reliable sequenced delivery is not guaranteed. Quote Link to comment Share on other sites More sharing options...
redlex Posted August 24, 2007 Report Share Posted August 24, 2007 >Error recovery routines, MTU, etc. Ah ok. >>Both use TCP/IP. >Um, only if the program opens a TCP connection. If a UDP >connection is opened, reliable sequenced delivery is not guaranteed. Does the software use UDP sometimes? Under what conditions? Quote Link to comment Share on other sites More sharing options...
rhwalker Posted August 24, 2007 Report Share Posted August 24, 2007 Quote: Does the software use UDP sometimes? Under what conditions? Yes: Retrospect ports and protocols I believe that UDP is used for the backup data transfers because of its lower overhead. You could use netstat to look at open ports and data transfers while a backup is going on. Quote Link to comment Share on other sites More sharing options...
redlex Posted August 24, 2007 Report Share Posted August 24, 2007 thanks! Quote Link to comment Share on other sites More sharing options...
redlex Posted August 30, 2007 Report Share Posted August 30, 2007 We now have a direct host-to-host VPN from our retrospect backup server to the Windows2003 retrospect client we were getting errors with when going directlyt over the internet. However, I'm having no luck adding the VPN IP as a backup client though - get almost instant -519 communications error. I've specified the correct interface/adapter as well (i.e. the VPN adapter, not the default interface). On the retrospect server, I can do "telnet [VPN ip] 497" and get a connection to the retrospect client at the other end, so it's not a zero connectivity issue AFAICT. (And I can ping the VPN ip too.) Any ideas anyone? Quote Link to comment Share on other sites More sharing options...
rhwalker Posted August 30, 2007 Report Share Posted August 30, 2007 Quote: Any ideas anyone? If you are using VPN, then there's some hardware or software at each end handling the ends of the tunnel. (we use SonicWALL for our VPN, don't know what you use). VPN is a bag of screaming cats. Again, the VPN endpoints could be blocking UDP for port 497. Or there may be a firewall on one or both ends that is blocking UDP for port 497. Telnet establishes a TCP/IP connection, and doesn't use UDP, so you haven't tested whether UDP packets pass. And there could be MTU issues through the tunnel, and/or something in the path could be mucking about with the Don't Fragment bit packets (if set), etc. Just some ideas to test. Personally, I've never tried Retrospect through our SonicWALL VPN tunnel. Might be interesting. Russ Quote Link to comment Share on other sites More sharing options...
satz Posted September 5, 2007 Report Share Posted September 5, 2007 I have been using Retrospect over the internet for quite a while. I had to open firewalls to get to port TCP port 497. As far as I can tell UDP is used for the multicast discovery of the clients. I haven't checked if it is also used for the data transfer on the local area network. I have been trying to use Retrospect over ssh tunnels to get past firewalls I cannot open port 497. I get the error: 1189004767: connTCPConnection: non-stream packet too large: 1771362658 when I try the initial connection dialog. From what I can glean looking at packet traces the same data exchange occurs but the contents is different. I cannot tell why I am getting this error. I have tried using the same IP subnet address and a different IP network address for the local side of the tunnel but both give this same result. Any clues appreciated. Thanks. Quote Link to comment Share on other sites More sharing options...
satz Posted September 6, 2007 Report Share Posted September 6, 2007 Looking at the packet traces some more, I noticed that the server opens and closes the connection to the client three times. I believe it is doing this to determine latency/round trip times. If I insert too many tunnels/TCP connections between the server and the client, I will get the packet too large error. Quote Link to comment Share on other sites More sharing options...
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