You are viewing a plain text version of this content. The canonical link for it is here.
Posted to issues@cloudstack.apache.org by "Sean Lair (JIRA)" <ji...@apache.org> on 2018/05/29 21:05:00 UTC
[jira] [Comment Edited] (CLOUDSTACK-10379) Using Source NAT option
on Private Gateway does not work
[ https://issues.apache.org/jira/browse/CLOUDSTACK-10379?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16494264#comment-16494264 ]
Sean Lair edited comment on CLOUDSTACK-10379 at 5/29/18 9:04 PM:
-----------------------------------------------------------------
[~weizhou] Here is the command output:
{code:java}
root@r-313-VM:~# ip route
default via 46.99.52.1 dev eth1
10.0.0.0/24 dev eth2 proto kernel scope link src 10.0.0.1
10.101.141.0/30 dev eth3 proto kernel scope link src 10.101.141.2
46.99.52.0/26 dev eth1 proto kernel scope link src 46.99.52.18
169.254.0.0/16 dev eth0 proto kernel scope link src 169.254.2.12
root@r-313-VM:~# ip rule
0: from all lookup local
32761: from all fwmark 0x3 lookup Table_eth3
32762: from all fwmark 0x2 lookup Table_eth2
32763: from all fwmark 0x1 lookup Table_eth1
32764: from 10.0.0.0/16 lookup static_route_back
32765: from 10.0.0.0/16 lookup static_route
32766: from all lookup main
32767: from all lookup default
root@r-313-VM:~# ip route show table Table_eth1
default via 49.99.52.1 dev eth1 proto static
root@r-313-VM:~# ip route show table Table_eth2
root@r-313-VM:~# ip route show table Table_eth3
{code}
was (Author: slair1):
[~weizhou] Here is the command output:
{code:java}
root@r-313-VM:~# ip route
default via 46.99.52.1 dev eth1
10.0.0.0/24 dev eth2 proto kernel scope link src 10.0.0.1
10.101.141.0/24 dev eth3 proto kernel scope link src 10.101.141.10
46.99.52.0/26 dev eth1 proto kernel scope link src 46.99.52.18
169.254.0.0/16 dev eth0 proto kernel scope link src 169.254.2.12
root@r-313-VM:~# ip rule
0: from all lookup local
32761: from all fwmark 0x3 lookup Table_eth3
32762: from all fwmark 0x2 lookup Table_eth2
32763: from all fwmark 0x1 lookup Table_eth1
32764: from 10.0.0.0/16 lookup static_route_back
32765: from 10.0.0.0/16 lookup static_route
32766: from all lookup main
32767: from all lookup default
root@r-313-VM:~# ip route show table Table_eth1
default via 49.99.52.1 dev eth1 proto static
root@r-313-VM:~# ip route show table Table_eth2
root@r-313-VM:~# ip route show table Table_eth3
{code}
> Using Source NAT option on Private Gateway does not work
> --------------------------------------------------------
>
> Key: CLOUDSTACK-10379
> URL: https://issues.apache.org/jira/browse/CLOUDSTACK-10379
> Project: CloudStack
> Issue Type: Improvement
> Security Level: Public(Anyone can view this level - this is the default.)
> Components: VPC
> Affects Versions: 4.9.0, 4.10.0.0
> Environment: KVM
> Reporter: Sean Lair
> Priority: Minor
> Labels: patch
> Original Estimate: 24h
> Remaining Estimate: 24h
>
> There is a bug in the Private Gateway functionality, when Source NAT is enabled for the Private Gateway. When the SNAT is added to iptables, it has the source CIDR of the private gateway subnet. Since no VMs live in that private gateway subnet, the SNAT doesn’t work. Below is an example:
>
> * VMs have IP addresses in the 10.0.0.0/24 subnet.
> * The Private Gateway address is 10.101.141.2/30
>
> See the outputs below, see how the SOURCE field for the new SNAT (eth3) only matches if the source is 10.101.141.0/30? Since the VM has an IP address in 10.0.0.0/24, the VMs don’t get SNAT’d as they should when talking across the private gateway. The SOURCE should be set to ANYWHERE.
>
> BEFORE ADDING PRIVATE GATEWAY
> -----------------------------------------------
> {code:java}
> Chain POSTROUTING (policy ACCEPT 1 packets, 52 bytes)
> pkts bytes target prot opt in out source destination
> 2 736 SNAT all -- any eth2 10.0.0.0/24 anywhere to:10.0.0.1
> 16 1039 SNAT all -- any eth1 anywhere anywhere to:46.99.52.18{code}
>
> AFTER ADDING PRIVATE GATEWAY W/ SNAT
> -----------------------------------------------
> {code:java}
> Chain POSTROUTING (policy ACCEPT 0 packets, 0 bytes)
> pkts bytes target prot opt in out source destination
> 0 0 SNAT all -- any eth3 10.101.141.0/30 anywhere to:10.101.141.2
> 2 736 SNAT all -- any eth2 10.0.0.0/24 anywhere to:10.0.0.1
> 23 1515 SNAT all -- any eth1 anywhere anywhere to:46.99.52.18
> {code}
>
> It looks like CsAddress.py treats the creation of the Private Gateway SNAT as if it is a GUEST network, which works fine, except for the SNAT problem shown above. Here is the code from MASTER (line 479 is SNAT rule):
>
> {code:java}
> if self.get_type() in ["guest"]:
> ...
> ...
> self.fw.append(["nat", "front",
> "-A POSTROUTING -s %s -o %s -j SNAT --to-source %s" %
> (guestNetworkCidr, self.dev, self.address['public_ip'])])
> {code}
>
> I am thinking we just change that to the following. I can’t think of any reason we need the source/guest CIDR specified:
>
> {code:java}
> if self.get_type() in ["guest"]:
> ...
> ...
> self.fw.append(["nat", "front",
> "-A POSTROUTING -o %s -j SNAT --to-source %s" %
> (self.dev, self.address['public_ip'])])
> {code}
>
> THE NAT TABLE IF THE ABOVE CODE CHANGE IS MADE
> -----------------------------------------------
> {code:java}
> Chain POSTROUTING (policy ACCEPT 0 packets, 0 bytes)
> pkts bytes target prot opt in out source destination
> 0 0 SNAT all -- any eth3 anywhere anywhere to:10.101.141.2
> 2 736 SNAT all -- any eth2 anywhere anywhere to:10.0.0.1
> 23 1515 SNAT all -- any eth1 anywhere anywhere to:46.99.52.18
> {code}
>
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)