Two Network Interfaces on Same Subnet -- How-To?

Two Network Interfaces on Same Subnet -- How-To?

Post by Jonathan B. Hore » Thu, 04 Feb 1999 04:00:00



Shalom!

Our Sparc20 clone has two LE network interfaces -- le0 and le2.  I would
like to use both interfaces, in the hope of doubling the throughput to
our Cisco FastEthernet switches (right: it would be best if Management
would spring for a 100Mbit/s hme card...).

This is what I've done so far:

1.  copied /etc/hostname.le0 to /etc/hostname.le2
2.  added a second entry for the host (with a different IP address)
    to /etc/hosts
3.  added an entry for the host (with a different IP address) to the
    DNS tables (and restarted named)
4.  ifconfig le2 <ip_address> up netmask <netmask> broadcast <broadcast>
    -trailers

5.  ifconfig le2 plumb

At this point "ifconfig -a" shows the second interface as it should be;
however, "netstat -rn" shows no use for interface le2.

194.90.208.0         194.90.208.2          U       12   1529  le0
194.90.208.0         194.90.208.7          U        2      0  le2

In addition, running "snoop -d le2" only shows me ARP and host-id packet
traffic, but the interface isn't being used for "regular" traffic.

What have I missed?

Thanks in advance.

--
JONATHAN B. HOREN                            UNIX SYSTEM ADMINISTRATION

                                                   -- Clare Boothe Luce

 
 
 

Two Network Interfaces on Same Subnet -- How-To?

Post by Casper H.S. Dik - Network Security Engine » Thu, 04 Feb 1999 04:00:00


[[ PLEASE DON'T SEND ME EMAIL COPIES OF POSTINGS ]]


Quote:>Our Sparc20 clone has two LE network interfaces -- le0 and le2.  I would
>like to use both interfaces, in the hope of doubling the throughput to
>our Cisco FastEthernet switches (right: it would be best if Management
>would spring for a 100Mbit/s hme card...).
>This is what I've done so far:
>1.  copied /etc/hostname.le0 to /etc/hostname.le2

Wrong; the "hostname.leX" file should not contain the hostname but rather
the name of the alias used for that interface.
(Or the IP addresses themselves).

hostname.le0 should contain something like "hostname-ether0"
hostname.le2 should contain something like "hostname-ether2"
nodename contains the hostname proper ("hostname").

/etc/hosts should be setup like this:

IP-for-le0      hostname hostname-ether0
IP-for-le2      hostname hostname-ether2

These per interface aliases can be added to DNS if they're used outside
the host.  Personally, I also prefer to specify the FQDN first:

IP-for-le0      hostname.your.domain hostname hostname-ether0
IP-for-le2      hostname.your.domain hostname hostname-ether2

This makes for a consistent behaviour between /etc/hosts and
DNS.

Quote:>2.  added a second entry for the host (with a different IP address)
>    to /etc/hosts

See above.

Quote:>3.  added an entry for the host (with a different IP address) to the
>    DNS tables (and restarted named)

fine.

Quote:>4.  ifconfig le2 <ip_address> up netmask <netmask> broadcast <broadcast>
>    -trailers
>5.  ifconfig le2 plumb
>At this point "ifconfig -a" shows the second interface as it should be;
>however, "netstat -rn" shows no use for interface le2.
>194.90.208.0         194.90.208.2          U       12   1529  le0
>194.90.208.0         194.90.208.7          U        2      0  le2
>In addition, running "snoop -d le2" only shows me ARP and host-id packet
>traffic, but the interface isn't being used for "regular" traffic.
>What have I missed?

Well, you need to run Solaris 2.6+
You need to enable group infs (set ip:ip_enable_group_ifs = 1 in /etc/system)
You need to set a different ethernet address for the second interface.

Casper
--
Expressed in this posting are my opinions.  They are in no way related
to opinions held by my employer, Sun Microsystems.
Statements on Sun products included here are not gospel and may
be fiction rather than truth.

 
 
 

Two Network Interfaces on Same Subnet -- How-To?

Post by Richard L. Hamilt » Thu, 04 Feb 1999 04:00:00


Suns tend to use the MAC (low-level Ethernet) address of the
built-in interface for all interfaces.  That only becomes
a problem when one tries to put two interfaces on the same
LAN.

You need to set the Ethernet address for the 2nd interface.
For example, if the address of the 1st interface is
8:0:20:11:fb:29, pick another address to use for the 2nd
interface.  It must be unique, at least among all the interfaces
behind the same router.

Assuming the new address was 8:0:20:11:de:af, the command to
set it would be
   ifconfig le2 ether 8:0:20:11:de:af

That will only last until the next reboot.  To make it permanent,
you need to create a suitable startup script to issue that command
every time the system boots.



> Shalom!

> Our Sparc20 clone has two LE network interfaces -- le0 and le2.  I would
> like to use both interfaces, in the hope of doubling the throughput to
> our Cisco FastEthernet switches (right: it would be best if Management
> would spring for a 100Mbit/s hme card...).

> This is what I've done so far:

> 1.  copied /etc/hostname.le0 to /etc/hostname.le2
> 2.  added a second entry for the host (with a different IP address)
>     to /etc/hosts
> 3.  added an entry for the host (with a different IP address) to the
>     DNS tables (and restarted named)
> 4.  ifconfig le2 <ip_address> up netmask <netmask> broadcast <broadcast>
>     -trailers

> 5.  ifconfig le2 plumb

> At this point "ifconfig -a" shows the second interface as it should be;
> however, "netstat -rn" shows no use for interface le2.

> 194.90.208.0         194.90.208.2          U       12   1529  le0
> 194.90.208.0         194.90.208.7          U        2      0  le2

> In addition, running "snoop -d le2" only shows me ARP and host-id packet
> traffic, but the interface isn't being used for "regular" traffic.

> What have I missed?

> Thanks in advance.

> --
> JONATHAN B. HOREN                            UNIX SYSTEM ADMINISTRATION

>                                                    -- Clare Boothe Luce

--
ftp> get |fortune
377 I/O error: smart remark generator failed

Bogonics: the primary language inside the Beltway


 
 
 

Two Network Interfaces on Same Subnet -- How-To?

Post by Thong » Thu, 04 Feb 1999 04:00:00


              As these two interfaces are connected to the same subnet,
              you need to do something about the MAC address for le2 to
              make sure that it is unique.

Thong


: Shalom!

: Our Sparc20 clone has two LE network interfaces -- le0 and le2.  I would
: like to use both interfaces, in the hope of doubling the throughput to
: our Cisco FastEthernet switches (right: it would be best if Management
: would spring for a 100Mbit/s hme card...).

: This is what I've done so far:

: 1.  copied /etc/hostname.le0 to /etc/hostname.le2
: 2.  added a second entry for the host (with a different IP address)
:     to /etc/hosts
: 3.  added an entry for the host (with a different IP address) to the
:     DNS tables (and restarted named)
: 4.  ifconfig le2 <ip_address> up netmask <netmask> broadcast <broadcast>
:     -trailers

: 5.  ifconfig le2 plumb

: At this point "ifconfig -a" shows the second interface as it should be;
: however, "netstat -rn" shows no use for interface le2.

: 194.90.208.0         194.90.208.2          U       12   1529  le0
: 194.90.208.0         194.90.208.7          U        2      0  le2

: In addition, running "snoop -d le2" only shows me ARP and host-id packet
: traffic, but the interface isn't being used for "regular" traffic.

: What have I missed?

: Thanks in advance.

: --
: JONATHAN B. HOREN                            UNIX SYSTEM ADMINISTRATION

:                                                    -- Clare Boothe Luce

--
Thong Ly                        Merrill *

Tel: +1-212-558-0587            20 Broad Street, 14F
Fax: +1-212-558-0578            New York, NY 10005

 
 
 

Two Network Interfaces on Same Subnet -- How-To?

Post by Casper H.S. Dik - Network Security Engine » Fri, 05 Feb 1999 04:00:00


[[ PLEASE DON'T SEND ME EMAIL COPIES OF POSTINGS ]]


>what's ip:ip_enable_group_ifs = 1 do?

No need to quote the entire article for that question.

It enables round-robin IP for multiple interfaces on the same net.

Casper
--
Expressed in this posting are my opinions.  They are in no way related
to opinions held by my employer, Sun Microsystems.
Statements on Sun products included here are not gospel and may
be fiction rather than truth.

 
 
 

Two Network Interfaces on Same Subnet -- How-To?

Post by Rick Jon » Sat, 06 Feb 1999 04:00:00



: It enables round-robin IP for multiple interfaces on the same net.

Will that be packet by packet, or connection by connection, (for what
definition of a "connection" - eg how about NFS?).

I suppose the importance depends on what the original poster was
expecting to get - a single FTP that could now go at 20 Mbit/s, or an
aggregate of 20 Mbit/s across a number of FTP's (or other things...).

rick jones

--
these opinions are mine, all mine; HP might not want them anyway... :)
feel free to email, or post, but please do not do both...
my email address is raj in the cup.hp.com domain...

 
 
 

Two Network Interfaces on Same Subnet -- How-To?

Post by David Com » Tue, 23 Feb 1999 04:00:00



>Will that be packet by packet, or connection by connection, (for what
>definition of a "connection" - eg how about NFS?).

It's on a per-destination basis - so if all of your traffic is headed
to a single destination, you're out of luck.  On the other hand, if
you're a global web-server with thousands of client coming in, you
should get a nice balance.

dsc

 
 
 

Two Network Interfaces on Same Subnet -- How-To?

Post by Rick Jon » Wed, 24 Feb 1999 04:00:00



: >Will that be packet by packet, or connection by connection, (for what
: >definition of a "connection" - eg how about NFS?).

: It's on a per-destination basis - so if all of your traffic is
: headed to a single destination, you're out of luck.  On the other
: hand, if you're a global web-server with thousands of client coming
: in, you should get a nice balance.

Is anything done to match the inbound interface with the outbound
interface?

rick jones
--
these opinions are mine, all mine; HP might not want them anyway... :)
feel free to email, or post, but please do not do both...
my email address is raj in the cup.hp.com domain...

 
 
 

1. One DHCP server - two interfaces - two subnets

Hi
        I run a DHCP server which supports wired internet in the internal LAN range
192.168.0.1/24. Now I wish to add a wireless internet LAN in the internal
LAN range 10.0.0.1/24. How do I accomplish this ?

/etc/dhcpd.conf :

option www-server       207.75.181.2,141.213.6.5,141.213.6.1;
ddns-update-style ad-hoc;

subnet 192.168.0.0 netmask 255.255.255.0
{
        range 192.168.0.3       192.168.0.10;

subnet 10.0.0.0 netmask 255.255.255.0
{
        range 10.0.0.3  10.0.0.10;

host clientwired
{
        hardware ethernet       wr:wr:wr:wr:wr:wr;
        fixed-address           192.168.0.2;

host clientwireless
{
        hardware ethernet       wl:wl:wl:wl:wl:wl;
        fixed-address           10.0.0.2;

where wr:wr:wr:wr:wr:wr and wl:wl:wl:wl:wl:wl are the obfuscated hardware
addresses for two clients - one wired and one wireless. How do I make sure
that the server listens on eth0 for the wired connections (192.168.0.1/24 -
as it already does) and wlan0 for wireless connections (10.0.0.1/24) ?

Thanks,

MS

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