Marty, if I run a telnet <www.xyz.com> 80 from a shell in the guest, while running a tcpdumpon the public i/f of the VR: - I can see the outbound packets going out- I do not see a response packet coming back in FYI there are no firewalls outbound from the KVM host. The host bridges vi CS networkingdirectly out on to the internet via a switch. Note that traffic from outside (ssh, web) can happily traverse the VR to the guest. I get the usualits working html page from the guest. This tells me that there is nothing outbound from the VR thatis filtering packets. Am truly stumped. This is mysterious indeed. >From within the VR, can happily telnet to <www.xyz.com> 80 and receive >response.Only if packet came from guest and was forwarded does the response >not show up. In short: wget from VR to www.xyz.com works, response received and saved wget from guest to www.xyz.com does not work, network not available displayed on guest, response packets not seen on the public i/f of VR at all Noel
> Date: Sun, 15 Sep 2013 18:16:17 +0100 > Subject: Re: Advanced Network - SNAT not working > From: [email protected] > To: [email protected] > > Hi Noel, > > Can you answer: Does the traffic come back on the public interface? and > then onto the Guest interface? > > Thanks, > Marty > > > On Sun, Sep 15, 2013 at 2:05 PM, Noel Kendall <[email protected]>wrote: > > > Indeed, yes, a wget executed on the VR to a public website works just fine. > > Noel > > > > > Date: Sun, 15 Sep 2013 13:15:20 +0100 > > > Subject: Re: Advanced Network - SNAT not working > > > From: [email protected] > > > To: [email protected] > > > > > > Hi Noel, > > > > > > Does the traffic come back on the public interface? and then onto the > > Guest > > > interface? > > > > > > Does a wget on the VR work? > > > > > > Marty > > > > > > > > > On Sat, Sep 14, 2013 at 8:19 PM, Noel Kendall <[email protected] > > >wrote: > > > > > > > I have that Marty. I see the http outbound request coming in on the > > guest > > > > interface of the VR,and see the http request being sent out on the > > public > > > > interface of the VR. > > > > The traffic is flowing fine from guest to the outbound i/f of the VR. > > > > This is tcpdump on the public i/f while guest is doing wget to > > > > 6x.xxx.xxx.xxx > > > > > > > > 19:17:58.834932 06:e3:3a:00:01:0a > 00:0c:86:4e:fe:00, ethertype IPv4 > > > > (0x0800), length 74: 10.11.79.178.39074 > 6x.xxx.xxx.xx.80: Flags [S], > > seq > > > > 1859313238, win 14600, options [mss 1460,sackOK,TS val 27489348 ecr > > > > 0,nop,wscale 4], length 0 0x0000: 4500 003c ad1d 4000 3f06 2d13 0a0b > > 4fb2 > > > > 0x0010: 416e c660 98a2 0050 6ed2 de56 0000 0000 0x0020: > > > > a002 3908 516c 0000 0204 05b4 0402 080a 0x0030: 01a3 7444 0000 > > > > 0000 0103 0304 > > > > > > > > > > > > > Date: Sat, 14 Sep 2013 19:29:53 +0100 > > > > > Subject: Re: Advanced Network - SNAT not working > > > > > From: [email protected] > > > > > To: [email protected] > > > > > > > > > > Hi Noel, > > > > > > > > > > Can you run a tcpdump on both VR interfaces, this should make it > > apparent > > > > > what is happening? > > > > > > > > > > Thanks, > > > > > Marty > > > > > > > > > > > > > > > On Sat, Sep 14, 2013 at 6:41 PM, Noel Kendall < > > [email protected] > > > > >wrote: > > > > > > > > > > > http://pastebin.com/3FZmFnvZ > > > > > > Many thanks Marty. > > > > > > Noel > > > > > > > Date: Sat, 14 Sep 2013 18:07:55 +0100 > > > > > > > Subject: Re: Advanced Network - SNAT not working > > > > > > > From: [email protected] > > > > > > > To: [email protected] > > > > > > > > > > > > > > Hi Noel, > > > > > > > > > > > > > > Could you put the IP tables on pastebin? GMail has collapsed the > > > > lines > > > > > > > horrifically. > > > > > > > Have you also tried a tcpdump on both interfaces on the VR? > > > > > > > tcpdump -i eth0 <--- Or whatever it may be called > > > > > > > > > > > > > > I would expect worse connectivity if it was a pure NAT issue, > > but I > > > > will > > > > > > > review the tables later. > > > > > > > > > > > > > > Thanks, > > > > > > > Marty > > > > > > > > > > > > > > > > > > > > > On Sat, Sep 14, 2013 at 5:55 PM, Noel Kendall < > > > > [email protected] > > > > > > >wrote: > > > > > > > > > > > > > > > Not seeing return packets on VR. Suspect, therefore, that SNAT > > is > > > > > > fouled > > > > > > > > up in some way.I have been doing wget to from guest, can see > > the > > > > > > outgoing > > > > > > > > request fine, both in the guest andthe VR. > > > > > > > > Could it be that the SNAT table entries from the > > 10.11.0.0/16subnet > > > > > > to > > > > > > > > dpt www are interfering withthe SNAT to public ip?? (wild > > guess) - > > > > not > > > > > > an > > > > > > > > iptables expert by any stretch of the imagination > > > > > > > > 67.xxx.xxx.56 is the guest public IP10.11.79.178 is the guest > > IP on > > > > > > guest > > > > > > > > network > > > > > > > > iptables _L -t nat on the VR shows... > > > > > > > > Chain PREROUTING (policy ACCEPT)target prot opt source > > > > > > > > destination DNAT tcp -- anywhere > > > > anywhere > > > > > > > > tcp dpt:domain to:10.11.0.1 DNAT tcp -- anywhere > > > > > > > > 67.xxx.xxx.56 tcp dpt:www to:10.11.79.178:80 DNAT > > > > tcp -- > > > > > > > > anywhere 67.xxx.xxx.56 tcp dpt:www > > > > > > to:10.11.79.178:80DNAT tcp -- anywhere > > > > 67.xxx.xxx.56 > > > > > > tcp dpt:https > > > > > > > > to:10.11.79.178:443 DNAT tcp -- anywhere > > > > > > > > 67.xxx.xxx.56 tcp dpt:https to:10.11.79.178:443 DNAT > > > > tcp > > > > > > -- > > > > > > > > anywhere 67.xxx.xxx.56 tcp dpt:ssh > > > > > > to:10.11.79.178:22DNAT tcp -- anywhere > > > > 67.xxx.xxx.56 > > > > > > tcp dpt:ssh > > > > > > > > to:10.11.79.178:22 DNAT tcp -- anywhere > > > > > > 67.xxx.xxx.56 > > > > > > > > tcp dpt:ftp to:10.11.79.178:21 DNAT tcp -- > > anywhere > > > > > > > > 67.xxx.xxx.56 tcp dpt:ftp to:10.11.79.178:21 DNAT > > > > > > tcp > > > > > > > > -- anywhere 67.xxx.xxx.56 tcp dpt:5901 to: > > > > > > > > 10.11.79.178:5901 DNAT tcp -- anywhere > > > > > > 67.xxx.xxx.56 > > > > > > > > tcp dpt:5901 to:10.11.79.178:5901 > > > > > > > > Chain POSTROUTING (policy ACCEPT)target prot opt source > > > > > > > > destination SNAT all -- anywhere > > > > anywhere > > > > > > > > to:67.xxx.xxx.56 SNAT all -- anywhere > > > > > > anywhere > > > > > > > > to:67.xxx.xxx.56 SNAT all -- anywhere > > > > > > > > anywhere to:67.xxx.xxx.56 SNAT all -- > > anywhere > > > > > > > > anywhere to:67.xxx.xxx.56 SNAT all -- > > anywhere > > > > > > > > anywhere to:67.xxx.xxx.56SNAT all -- > > > > anywhere > > > > > > > > anywhere to:67.xxx.xxx.56 SNAT all -- > > > > anywhere > > > > > > > > anywhere to:67.xxx.xxx.56 SNAT all -- > > > > > > anywhere > > > > > > > > anywhere to:67.xxx.xxx.56 SNAT tcp > > -- > > > > > > > > 10.11.0.0/16 myguest tcp dpt:www > > to:10.11.0.1 > > > > SNAT > > > > > > > > tcp -- 10.11.0.0/16 myguest tcp > > > > dpt:https > > > > > > > > to:10.11.0.1 SNAT tcp -- 10.11.0.0/16 myguest > > > > > > > > tcp dpt:ssh to:10.11.0.1 SNAT tcp -- 10.11.0.0/16 > > > > > > myguest > > > > > > > > tcp dpt:ftp to:10.11.0.1 SNAT tcp -- > > > > 10.11.0.0/16 > > > > > > > > myguest tcp dpt:5901 to:10.11.0.1 SNAT > > all > > > > -- > > > > > > > > anywhere anywhere to:67.xxx.xxx.56 > > > > > > > > Chain OUTPUT (policy ACCEPT)target prot opt source > > > > > > > > destination DNAT tcp -- anywhere > > > > > > 67.xxx.xxx.56 > > > > > > > > tcp dpt:www to:10.11.79.178:80 DNAT tcp -- > > anywhere > > > > > > > > 67.xxx.xxx.56 tcp dpt:https to:10.11.79.178:443 DNAT > > > > > > tcp > > > > > > > > -- anywhere 67.xxx.xxx.56 tcp dpt:ssh to: > > > > > > > > 10.11.79.178:22 DNAT tcp -- anywhere > > > > 67.xxx.xxx.56 > > > > > > > > tcp dpt:ftp to:10.11.79.178:21 DNAT tcp -- > > anywhere > > > > > > > > 67.xxx.xxx.56 tcp dpt:5901 to:10.11.79.178:5901 > > > > > > > > > > > > > > > > > Date: Sat, 14 Sep 2013 17:25:14 +0100 > > > > > > > > > Subject: Re: Advanced Network - SNAT not working > > > > > > > > > From: [email protected] > > > > > > > > > To: [email protected] > > > > > > > > > > > > > > > > > > Hi Noel, > > > > > > > > > > > > > > > > > > Can you try using telnet to connect to an external webserver? > > > > telnet > > > > > > > > > www.google.com 80 > > > > > > > > > Can you also clarify: do you see the response packets reach > > the > > > > VR > > > > > > and/or > > > > > > > > > on what interfaces? > > > > > > > > > > > > > > > > > > Thanks, > > > > > > > > > Marty > > > > > > > > > > > > > > > > > > On Saturday, September 14, 2013, Noel Kendall wrote: > > > > > > > > > > > > > > > > > > > Guest OS cannot receive responses to http GETs from > > resources > > > > on > > > > > > the > > > > > > > > > > Internet. > > > > > > > > > > Network is advanced, VLAN isolated. > > > > > > > > > > What is working: > > > > > > > > > > - can browse guest website from internet- can ssh to guest > > from > > > > > > > > internet- > > > > > > > > > > can VPN to guest network from internet > > > > > > > > > > - network VR can access internet sites no problem > > > > > > > > > > What is not working: > > > > > > > > > > - guest http traffic to external website gets to VR on > > internal > > > > > > NIC, > > > > > > > > > > packets forwarded to external site via external NIC > > > > > > > > > > > > > > > > > > > > Response traffic is not seen. Appears to be dropped. > > > > > > > > > > Have been looking hard at IPTABLES rules, doing tcpdumps, > > etc. > > > > > > > > > > Am at this point stumped. > > > > > > > > > > Any ideas on what could be wrong, or how to determine what > > > > could be > > > > > > > > wrong? > > > > > > > > > > Thanks in advance everyone who tries to help! > > > > > > > > > > N. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > >
