Arch Linux

duikertje59

Member

Registered: 2016-09-19

Posts: 2

Configuration of 2 Network cards, 1X internet and 1X internal network

Hi,

Coming from Debian based distro's I finally switched to Arch. So still in a steep learning curve. I installed arch with dhcpd and without network manager as I've bad experience with that in the setup I have. So actual situation:

enp3so for internet and enp5s2 for seperate network connected to an nas using jumbo frames at mtu 7000 over nfs protcol, where as the nas is configured with a static ip 192.168.xxx.xxx on netmask 255.255.0.0

Internet is curretnly working enp5s2 is not.

I tried to make netctl rule for this second card as per wiki but as soon as I start it, it gives and error and investigating this error it tells me that it is already running. If I take down dpcpd than also internet is gone .

I'm not sure if hosts/ hostnames has an influence here as well as I've seen things related to that as well but in a different setup again.

In Debain this was quiet easy with /etc/interfaces but works differently in Arch.....just can't figure it out though. some refer to dhcp others to netctl....and I'm not sure if i've to systemctl disable dhcpd to make netctl to work and vise versa.

Can somebody help this newbee?

Thanks.

ewaller

Administrator

From: Pasadena, CA

Registered: 2009-07-13

Posts: 19,772

Re: Configuration of 2 Network cards, 1X internet and 1X internal network

Welcome to the Arch Linux forums.

Your post is a little confusing.  If I understand, you have internet connectivity on enp3s0.  I presume you have a router on that network that is providing DHCP services.  I am guessing this is a 192.168.1.x/24 network.  Can you verify this and, if not, provide the IP address information for this network?

As to the enp5s2 network:  a 192.168.x.x/16 network is highly unusual.   One of the big problems with this is the 192.168.1.x/24 network on enp3s0 is also a valid address in the 192.168.x.x/16 address space that is on enp5s2.
What provides addresses on the enp5s2  network? Are you using static addresses, or is there a DHCP server on that network as well?

My recommendation is to configure the router for the network attached to enp3s0 as a 192.168.1.x/24 network, and the network connected to enp5s2 as a 192.168.2.x/24 (That means a net mask of 255.255.255.0).  If there is no DHCP server on that network, I would set one up on the Arch box, but static addresses will work just as well.    I assume you don't need (or want) the network attached to enp5s2 to have Internet connectivity (no NAT or bridge to enp3s0 )

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duikertje59

Member

Registered: 2016-09-19

Posts: 2

Re: Configuration of 2 Network cards, 1X internet and 1X internal network

Thanks for your reply. The enp3s0 is indeed over a router connected but completely different ip. 10.0.100.XXX as set up and ofcoursce netmask /24. so that connection is running fine over the dhcpd as it is. But how to configure the other one with static ip, jumbo frames mtu=7000 to run simulatneously. I made a profile in netctl but once I run it, it tells that enp5s2 is already running....probably also from dhcpd. enp5s2 has besides other iprange in 192.168.XX netmask 255.255.0.0 which is /16 as far i know.

/etc/netctl/enp5s2

Description='A basic static ethernet connection'
Interface=enp5s2
Connection=ethernet
IP=static
Address=('192.168.1.XXX/16')
#Routes=('192.168.0.0/24 via 192.168.1.2')
Gateway='192.168.1.XXX'  which is IP from NAS
DNS=('192.168.1.XXX') same as Address
------------------------------------------------------------------------------

No internet needed indeed on this one. And i'm struggling here also with how to define the mtu 7000. Besides that I can't activate it as soon as i do a netctl start it gives an error to tell that enp5s2 is running already.

Made also a static one now for enp3s0 and removed dhcpcd.
sudo netctl enable enp3s0
sudo netctl enable enp5s2

after reboot enp5s2 not working.

output from ip addr on this:

enp5s2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 90:e2:xx:xx:xx:xx brd ff:ff:ff:ff:ff:ff
    inet6 fexx::xxe2:baff:xxxx:696/64 scope link
       valid_lft forever preferred_lft forever

Last edited by duikertje59 (2016-09-22 18:06:56)