03-09-2017
Quote:
Originally Posted by
jim mcnamara
I don't quite get what you are trying to do. Maybe you want TAP - bridge from eth1: to eth0: Which you not have now. In other words segregate and bridge on this server. Is this box in the DMZ?
Mmmh. Ok let me try to eplain it...
The server hast 1 NIC (eth0) and is connected to the internet. There are several daemons running on it (Apache, FTP, ...). Now from time to time a script running on the machine has to connect by openvpn to some other servers of which I know only the domain name not the ip addresses because they change they rotate ips due load balancing and also have alot of IP ranges.
Now when script opens up a openvpn link (tun0) to connect to a openvpn host, all traffic of my server is then routed over the tun0 gateway. Therefor if some client tries to reach the Apache daemon under it's common address, he get's no reponse, because the reponse packet are not sent back on the eth0 interface but the tun0 route. So no more connection to the daemons are possible anymore until the openvpn connection is closed.
What I want now, is that the server responds to any ip packet it gets, on the same interface it was received. When the vpn link is up, all outgoing packets of tcp/udp traffic which were initiated by the server itself have to be routed to tun0, all answers on incoming packets on eth0 have to be answered to eth0.
Does this make any sense to you?
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dhcp6r(8) System Manager's Manual dhcp6r(8)
NAME
dhcp6r - DHCPv6 relay agent
SYNOPSIS
dhcp6r [ -d ] [ client-options ] [ server-options ]
DESCRIPTION
dhcp6r acts as DHCPv6 relay agent forwarding DHCPv6 messages from clients to servers and vice versa. DHCPv6 messages from clients are
received at UDP port 547, they are forwarded to one or more DHCPv6 servers by multicast and/or unicast. DHCPv6 messages from servers to
clients are also received at UDP port 547 and forwarded by unicast only.
DHCPv6 messages received by multicast at a certain IPv6 interface are never forwarded by multicast to the same interface.
If no options are present, the relay agent receives messages by unicast and multicast at all IPv6 interfaces, and all messages are for-
warded to all IPv6 interfaces by multicast with the exception mentioned in the previous paragraph.
If one or more client-options are present, then messages are only received as specified by the client options. If one or more server-
options are present, then messages are only forwarded as specified by the server options.
CLIENT-OPTIONS
If no client-options are present, the relay receives messages by multicast and unicast at all IPv6 interfaces.
If one or more client options are present, then messages are only received as specified by the client-options.
In any case, the relay receives client messages by unicast.
-cu This option can be used to configure the client such that it receives messages from clients or other relay agents by unicast only.
It does not have any effect if a -cm option is present.
-cm INTERFACE
Accept client messages multicasted at IPv6 interface INTERFACE. The others are receiving only unicast messages. For specifying a
set of interfaces, an instance of this option is required for each interface.
SERVER-OPTIONS
If no server-options are present, the relay forwards messages received from clients by multicast and unicast to all IPv6 interfaces, except
the one, which the packet was received on.
If one or more server-options are present, then messages are forwarded as specified by the server-options.
-sm INTERFACE
Forward all received client messages by multicast at IPv6 interface INTERFACE. For specifying a set of interfaces, an instance of
this option is required for each interface.
-su ADDRESS
Forward all received client messages by unicast to the IPv6 address ADDRESS. For specifying a set of addresses, an instance of this
option is required for each address.
-sf INTERFACE+ADDRESS
Forward all received client messages by unicast to the IPv6 address ADDRESS through the IPv6 interface INTERFACE. For specifying a
set of combinations of interfaces and addresses, an instance of this option is required for each combination.
The -sm, -su, and -sf options can be combined in arbitrary ways.
OTHER OPTIONS
-d If this option is not present, dhcp6r will dump logging information into the file /var/log/dhcp6r.log. If the option is present,
logging information will be sent to stderr instead.
EXAMPLES
The following examples are shown as given to the shell:
dhcp6r
Receive messages from clients at all IPv6 interfaces by multicast and by unicast, and forward them to all (other) IPv6 interfaces by
multicast.
dhcp6r -cu
Receive messages from clients by unicast only, and forward them to all (other) IPv6 interfaces by multicast.
dhcp6r -cm eth0 -cm eth2
Receive messages from clients at interfaces eth0 and eth2 by multicast and by unicast, and forward them to all IPv6 interfaces by
multicast (except the one at which the message was received by multicast).
dhcp6r -cm eth0 -cm eth2 -sm eth1
Receive messages from clients at interfaces eth0 and eth2 by multicast and by unicast, and forward them to interfaces eth1 by multi-
cast.
dhcp6r -su fec0::204:ce33:763f:b34 -su fec0::504:ff33:73f:c557
Receive messages from clients at all IPv6 interfaces by multicast and by unicast, and forward a copy of them to each of the speci-
fied addresses.
dhcp6r -sm eth1 -su fec0::204:ce33:763f:b34
Receive messages from clients at all IPv6 interfaces by multicast and by unicast, and forward them to interface eth1 by multicast
and to the specified unicast address.
dhcp6r -sm eth1 -sf eth0+fec0::504:ff33:73f:c557
Receive messages from clients at all IPv6 interfaces by multicast and by unicast, and forward them to interface eth1 by multicast
and to the specified unicast address. For the unicast address it is enforced that the message will be sent through interface eth0.
NOTES
For proper operation of dhcp6r, the host must have at least one global/site scope address assigned to each interface.
FILES
/var/log/dhcv6r.log /var/run/dhcpv6/dhcp6r.pid
BUGS
Report bugs via http://fedorahosted.org/dhcpv6/
AUTHORS
See http://fedorahosted.org/dhcpv6/wiki/Authors
dhcp6r(8)