Wed, 29 Feb 2012 13:13:59 +0100 > -----Ursprüngliche Nachricht----- > Von: Gordan Bobic [mailto:gordan@bobich.net] > Gesendet: Mittwoch, 29. Februar 2012 12:43 > An: vserver@list.linux-vserver.org > Betreff: Re: [vserver] Using loopback for guest-guest and guest-host > communication but still remapping > > Fiedler Roman wrote: > > Hi, > > > > I'm trying to configure networking on a machine, where we cannot use any > private network for internal communication because I might need to receive > traffic from that network. So I can only use loopback, one private IP-Range IP > (server external IP) and I do not want to grab one public IP-range for internal > communication if avoidable. > > > > Is this configuration with special combination of nflags and dev settings > possible (CAVEAT: network prefixes atypical)? > > > > * Guest ctx=3: Inside guest bind and connect to 127.0.0.1/24 is remapped > to 127.0.3.1 and stays inside guest > > * Guest ctx=4: Inside guest bind and connect to 127.0.0.1/24 is remapped > to 127.0.4.1 and stays inside guest > > > > * Guest ctx=3: Inside guest connect to 127.0.4.1/24 goes to guest ctx=4 > network stack (inter-guest comm) > > * Guest ctx=4: Inside guest connect to 127.0.3.1/24 goes to guest ctx=3 > network stack (inter-guest comm) > > > > * Guest ctx=3,4: Inside guest connects to any loopback IP-Range not bound > to any guest goes to host, e.g. 127.255.255.1 (if something is listening on host > on that IP/port) > > > > > > If not, would a special nflags, dev config configuration together with a > modification of vserver patch (change 127.0.0.0/8 to 127.0.0.0/24 > somewhere) be sufficient? > > I solved that problem by using a dummy interface for each internal-only > network. You set up a dummy interface on the host, and give the guests > an IP on that interface. I did a quick try of 10 configurations, but failed to get it working in combination with remap. How did your network config look like? Special nflags? Special kernel version or util-vservers? The one I'm trying to work on is (after startup of guest): Host: ~# ip addr show 1: lo: <LOOPBACK,UP,LOWER UP> mtu 16436 qdisc noqueue state UNKNOWN link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/24 scope host lo inet 127.0.2.1/24 brd 127.0.2.255 scope host lo 2: eth0: <BROADCAST,MULTICAST,UP,LOWER UP> mtu 1500 qdisc pfifo fast state UP qlen 1000 inet 192.168.0.2/24 scope global eth0 3: dummy0: <BROADCAST,NOARP,UP,LOWER UP> mtu 1500 qdisc noqueue state UNKNOWN inet 127.0.1.1/24 brd 127.0.1.255 scope host dummy0 inet 127.0.1.2/24 brd 127.0.1.255 scope host secondary dummy0 Guest vserver config: nflags: ~single ip,lback allow Dev 0: lo, 127.0.2.1/24 (context is 2) Dev 1: dummy0, 127.0.1.2/24 Guest ip addrs: /# ip addr show 1: lo: <LOOPBACK,UP,LOWER UP> mtu 16436 qdisc noqueue state UNKNOWN link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/24 scope host lo inet 127.0.2.1/24 brd 127.0.2.255 scope host lo 3: dummy0: <BROADCAST,NOARP,UP,LOWER UP> mtu 1500 qdisc noqueue state UNKNOWN link/ether 02:98:d9:0e:bd:a1 brd ff:ff:ff:ff:ff:ff inet 127.0.1.2/24 brd 127.0.1.255 scope host secondary dummy0 Connect from guest to 127.0.1.1:80 is still remapped to 127.0.2.1, which is guest itself. So no connection to host via lo possible.