[gentoo-user] Adding more than one static IP

[gentoo-user] Adding more than one static IP

[Amar Cosic]

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Hello list

My mind is just "locked" at the moment and I am trying to figure out what am
I doing wrong here. I have 4 static IP's on server machine and I have
something like this in /etc/conf.d/net :



config_eth0=( "77.xxx.104.14/24" )
routes_eth0=( "default via 77.xxx.104.1" )
config_eth0:1=( "77.xxx.104.100/24" )
routes_eth0:1=( "default via 77.xxx.104.1" )
config_eth0:2=( "77.xxx.104.101/24" )
routes_eth0:2=( "default via 77.xxx.104.1" )
config_eth0:3=( "77.xxx.105.100/24" )
routes_eth0:3=( "default via 77.xxx.105.1" )


eth0 works just fine while other ones fail. Could you help me with this one
?


ty.

--
Amar Ćosić
amar.cosic@gmail.com

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Re: [gentoo-user] Adding more than one static IP

[Alan McKinnon]

Apparently, though unproven, at 17:15 on Monday 24 January 2011, Amar Cosic 
did opine thusly:

> Hello list
> 
> My mind is just "locked" at the moment and I am trying to figure out what
> am I doing wrong here. I have 4 static IP's on server machine and I have
> something like this in /etc/conf.d/net :
> 
> 
> 
> config_eth0=( "77.xxx.104.14/24" )
> routes_eth0=( "default via 77.xxx.104.1" )
> config_eth0:1=( "77.xxx.104.100/24" )
> routes_eth0:1=( "default via 77.xxx.104.1" )
> config_eth0:2=( "77.xxx.104.101/24" )
> routes_eth0:2=( "default via 77.xxx.104.1" )
> config_eth0:3=( "77.xxx.105.100/24" )
> routes_eth0:3=( "default via 77.xxx.105.1" )
> 
> 
> eth0 works just fine while other ones fail. Could you help me with this one

You have aliased three additional IPs to a NIC. You cannot add routes to those 
aliases, only individual IP addresses.

You will either have to come up with a routing scheme that routes_eth0 fully 
satisfies or pony up the cash for three NIC cards.

I'd go for option 2 - NICs are dirt cheap.


-- 
alan dot mckinnon at gmail dot com

Re: [gentoo-user] Adding more than one static IP

[Graham Murray]

Amar Cosic <amar.cosic@gmail.com> writes:

> Hello list
>
> My mind is just "locked" at the moment and I am trying to figure out
> what am I doing wrong here. I have 4 static IP's on server machine
> and I have something like this in /etc/conf.d/net :
>
>
>
> config_eth0=( "77.xxx.104.14/24" )
> routes_eth0=( "default via 77.xxx.104.1" )
> config_eth0:1=( "77.xxx.104.100/24" )
> routes_eth0:1=( "default via 77.xxx.104.1" )
> config_eth0:2=( "77.xxx.104.101/24" )
> routes_eth0:2=( "default via 77.xxx.104.1" )
> config_eth0:3=( "77.xxx.105.100/24" )
> routes_eth0:3=( "default via 77.xxx.105.1" )
>
>
> eth0 works just fine while other ones fail. Could you help me with
> this one ?

Try emerging 'iproute2' (if not already installed) and then adding the
following line to /etc/iproute2/rt_tables
1   altlan


and then using the following in /etc/conf.d/net

modules-"iproute2"
config_eth0=( "77.xxx.104.14/24" "77.xxx.104.100/32" "77.xxx.104.101/32"
              "77.xxx.105.100/24" )
routes_eth0=( "default via 77.xxx.104.1"
              "default via 77.xxx.105.1 table altlan"
              "77.xxx.105.0/24 table altlan" )
rules_eth0=( "from 77.xxx.105.100 table altlan" )

postup() {
       # This function could be used, for example, to register with a
       # dynamic DNS service.  Another possibility would be to
       # send/receive mail once the interface is brought up.
       # Here is an example that allows the use of iproute rules
       # which have been configured using the rules_eth0 variable.
       #rules_eth0=" \
       #       'from 24.80.102.112/32 to 192.168.1.0/24 table localnet priority 100' \
       #       'from 216.113.223.51/32 to 192.168.1.0/24 table localnet priority 100' \
       #"
       eval set -- $\rules_${IFVAR}
       if [ $# != 0 ]; then
               einfo "Adding IP policy routing rules"
               eindent
               # Ensure that the kernel supports policy routing
               if ! ip rule list | grep -q "^"; then
                       eerror "You need to enable IP Policy Routing (CONFIG_IP_MULTIPLE_TABLES)"
                       eerror "in your kernel to use ip rules"
               else
                       for x; do
                               ebegin "${x}"
                               ip rule add ${x} dev "${IFACE}"
                               eend $?
                       done
               fi
               eoutdent
               # Flush the cache
               ip route flush cache dev "${IFACE}"
       fi
}

postdown() {
#      Automatically erase any ip rules created in the example postup above
       if interface_exists "${IFACE}"; then
               # Remove any rules for this interface
               local rule
               ip rule list | grep " iif ${IFACE}[ ]*" | {
                       while read rule; do
                               rule="${rule#*:}"       
                               ip rule del ${rule}
                       done
               }
               # Flush the route cache
               ip route flush cache dev "${IFACE}"
       fi

       # Return 0 always
       return 0
}

Re: [gentoo-user] Adding more than one static IP

[Walter Dnes]

On Mon, Jan 24, 2011 at 04:15:14PM +0100, Amar Cosic wrote
> Hello list
> 
> My mind is just "locked" at the moment and I am trying to figure out what am
> I doing wrong here. I have 4 static IP's on server machine

  I have one nic on my desktop.  It sits behind an ADSL router-modem
which has address 192.168.123.254.

* My little LAN is 192.168.123.248/29.  I want that to always go via the
  router/modem, so I give that path metric 0

* I have an HDHomerun TV tuner that pops up in the 169.254.0.0/16 block.
  That path also gets gets metric 0

* Default (i.e. to the internet) is metric 2 via the router

* Because the default is metric 2, dialup (temporary ppp0) can take over
  internet access, without interfering with LAN traffic or my TV tuner.

  Here's my /etc/conf.d.net

config_eth0=(
"192.168.123.249 broadcast 192.168.123.255 netmask 255.255.255.248 mtu 1454"
"169.254.1.3 broadcast 169.254.255.255 netmask 255.255.0.0")
routes_eth0=(
"default via 192.168.123.254 metric 2"
"192.168.123.248/29 via 192.168.123.254 metric 0"
"169.254.0.0/16 via 169.254.1.3 metric 0"
)

-- 
Walter Dnes <waltdnes@waltdnes.org>

Re: [gentoo-user] Adding more than one static IP

[Adam Carter]

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> config_eth0=( "77.xxx.104.14/24" )
> routes_eth0=( "default via 77.xxx.104.1" )
> config_eth0:1=( "77.xxx.104.100/24" )
> routes_eth0:1=( "default via 77.xxx.104.1" )
> config_eth0:2=( "77.xxx.104.101/24" )
> routes_eth0:2=( "default via 77.xxx.104.1" )
> config_eth0:3=( "77.xxx.105.100/24" )
> routes_eth0:3=( "default via 77.xxx.105.1" )
>

You should let us know what you're trying to achieve with this. Every time I
have seen config like this, it has been because of fundamental
misunderstandings of networking. More that one IP address on a subnet
(unless there are VIPs) = fail.

Remember routing occurs at layer 3, and for most configs should have no
reference physical interface. The OS knows which interface the next hop can
be found. In your config you've set the same route three times which makes
no sense.

(ok i've oversimplified, but for 99.9% of cases the above is true)

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Re: [gentoo-user] Adding more than one static IP

[Amar Cosic]

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On Tue, Jan 25, 2011 at 9:01 AM, Adam Carter <adamcarter3@gmail.com> wrote:

>
> config_eth0=( "77.xxx.104.14/24" )
>> routes_eth0=( "default via 77.xxx.104.1" )
>> config_eth0:1=( "77.xxx.104.100/24" )
>> routes_eth0:1=( "default via 77.xxx.104.1" )
>> config_eth0:2=( "77.xxx.104.101/24" )
>> routes_eth0:2=( "default via 77.xxx.104.1" )
>> config_eth0:3=( "77.xxx.105.100/24" )
>> routes_eth0:3=( "default via 77.xxx.105.1" )
>>
>
> You should let us know what you're trying to achieve with this. Every time
> I have seen config like this, it has been because of fundamental
> misunderstandings of networking. More that one IP address on a subnet
> (unless there are VIPs) = fail.
>
> Remember routing occurs at layer 3, and for most configs should have no
> reference physical interface. The OS knows which interface the next hop can
> be found. In your config you've set the same route three times which makes
> no sense.
>
> (ok i've oversimplified, but for 99.9% of cases the above is true)
>

I have this on Debian in /etc/network/interfaces:

auto lo
iface lo inet loopback
auto eth0
iface eth0 inet static
address 82.xxx.148.194
netmask 255.255.255.128
gateway 82.xxx.148.131
auto eth0:1
iface eth0:1 inet static
address 82.xxx.148.195
netmask 255.255.255.128
auto eth0:2
iface eth0:2 inet static
address 82.xxx.148.196
netmask 255.255.255.128
auto eth0:3
iface eth0:3 inet static
address 82.xxx.148.197
netmask 255.255.255.128


What I want to know is what is equivalent for this on Gentoo.  Let's just
say this is VPS server with 4 IP's assigned to me as customer


-- 
Amar Ćosić
amar.cosic@gmail.com

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Re: [gentoo-user] Adding more than one static IP

[Marius Vaitiekunas]

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On Tue, Jan 25, 2011 at 1:08 PM, Amar Cosic <amar.cosic@gmail.com> wrote:

>
>
> On Tue, Jan 25, 2011 at 9:01 AM, Adam Carter <adamcarter3@gmail.com>wrote:
>
>>
>> config_eth0=( "77.xxx.104.14/24" )
>>> routes_eth0=( "default via 77.xxx.104.1" )
>>> config_eth0:1=( "77.xxx.104.100/24" )
>>> routes_eth0:1=( "default via 77.xxx.104.1" )
>>> config_eth0:2=( "77.xxx.104.101/24" )
>>> routes_eth0:2=( "default via 77.xxx.104.1" )
>>> config_eth0:3=( "77.xxx.105.100/24" )
>>> routes_eth0:3=( "default via 77.xxx.105.1" )
>>>
>>
>> You should let us know what you're trying to achieve with this. Every time
>> I have seen config like this, it has been because of fundamental
>> misunderstandings of networking. More that one IP address on a subnet
>> (unless there are VIPs) = fail.
>>
>> Remember routing occurs at layer 3, and for most configs should have no
>> reference physical interface. The OS knows which interface the next hop can
>> be found. In your config you've set the same route three times which makes
>> no sense.
>>
>> (ok i've oversimplified, but for 99.9% of cases the above is true)
>>
>
> I have this on Debian in /etc/network/interfaces:
>
> auto lo
> iface lo inet loopback
> auto eth0
> iface eth0 inet static
> address 82.xxx.148.194
> netmask 255.255.255.128
> gateway 82.xxx.148.131
> auto eth0:1
> iface eth0:1 inet static
> address 82.xxx.148.195
> netmask 255.255.255.128
> auto eth0:2
> iface eth0:2 inet static
> address 82.xxx.148.196
> netmask 255.255.255.128
> auto eth0:3
> iface eth0:3 inet static
> address 82.xxx.148.197
> netmask 255.255.255.128
>
>
> What I want to know is what is equivalent for this on Gentoo.  Let's just
> say this is VPS server with 4 IP's assigned to me as customer
>
>
> --
> Amar Ćosić
> amar.cosic@gmail.com
>
>
Hi,

I am using like that in /etc/conf.d/net
-----
config_eth0=( "ip1 netmask 255.255.255.224"
               "ip2 netmask 255.255.255.255"
               "ip3 netmask 255.255.255.255"
)

routes_eth0=( "default via your_gw" )
-----

ifconfig doesn't show this info. I use ip command for that:

# ip addr

I hope it helps.
-- 
mv

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Re: [gentoo-user] Adding more than one static IP

[Bill Longman]

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On Mon, Jan 24, 2011 at 7:15 AM, Amar Cosic <amar.cosic@gmail.com> wrote:

> Hello list
>
> My mind is just "locked" at the moment and I am trying to figure out what
> am I doing wrong here. I have 4 static IP's on server machine and I have
> something like this in /etc/conf.d/net :
>
>
>
> config_eth0=( "77.xxx.104.14/24" )
> routes_eth0=( "default via 77.xxx.104.1" )
> config_eth0:1=( "77.xxx.104.100/24" )
> routes_eth0:1=( "default via 77.xxx.104.1" )
> config_eth0:2=( "77.xxx.104.101/24" )
> routes_eth0:2=( "default via 77.xxx.104.1" )
> config_eth0:3=( "77.xxx.105.100/24" )
> routes_eth0:3=( "default via 77.xxx.105.1" )
>
>
> eth0 works just fine while other ones fail. Could you help me with this one
> ?
>
>
Amar,

You should read up some more on how IP networking is configured and how it
works. A default route is, by definition, the next hop on the local network
to which packets are sent when no other local interface matches the intended
target IP address. Your IP stack looks for local interfaces which match the
target network for the target IP address. If it cannot find any, it has no
other recourse but to forward it to someone who might know better. That's
your default gateway router, and that's its job. If you tell your IP stack
that you have four default gateways, it will get very confused. Get rid of
all but one of those default route statements.

If, on the other hand, you just want your local machine to know the gateways
for those networks, your route statements should be of this form:

routes_eth:2=("77.xxx.104.101/24 via 77.xxx.104.1")

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