How best to connect two halves of network? Expert network advice needed.

[oshunluvr]

I have a nice Asus router on one end of my house. On the other end, I have my server that happened to have a built-in wi-fi card. I wasn't using the wi-fi card in the server until one evening I listened to my kids complain about the signal at that end of the house. I dove into the server and it's network config and managed to get the wi-fi card up as a wireless access point, and voila - we have two wifi access points.

The downsides to the server wi-fi access are:

1. I cannot get "N" class connections enabled, only "G", even though the card is N capable. My 'net research reveals this may be a firmware limitation so I gave up on it. This isn't a deal-breaker anyway.
2. I learned (rightly or wrongly) that I could only make it work at all if I used a different set of IP addresses.

#2 means while connected to the Asus router you get an IP range from 192.168.1.2 to 192.168.1.198 (a range I set to reserve fixed IP's) but while connected to the server AP you get 192.168.0.50 to 192.168.0.150.

This results in a solid and usable internet connection for ether connection, but devices connected to one AP cannot connect to various services on the other. Mostly, this involves my server itself which is hard-wired to the Asus router for it's connection but also KDE Connect cannot connect to my phone if I'm connected to the server AP instead of the router.

To get this to the state it's currently in, I muddled through dozens of networking AP how-to's until I landed on using hostapd to configure the AP.

Here's the contents (minus remarks) of /etc/dnsmasq.conf

server=8.8.4.4
server=198.153.194.1
interface=wlan0
dhcp-range=192.168.0.50,192.168.0.150,24h

Here's the entire contents of /etc/hostapd.d/hostapd.conf:

[FONT=monospace][COLOR=#000000]# WiFi Hotspot[/COLOR]
interface=wlan0
driver=nl80211
#Access Point
ssid=smithserver
hw_mode=g
# WiFi Channel:
channel=1
macaddr_acl=0
auth_algs=1
ignore_broadcast_ssid=0
wpa=2
wpa_passphrase=<NON_YA_BIN_ESS>
wpa_key_mgmt=WPA-PSK
wpa_pairwise=TKIP
rsn_pairwise=CCMP

# 802.11n (HT) is enabled
ieee80211n=1
ht_capab=[SHORT-GI-40][HT40+][HT40-][DSSS_CCK-40]
wmm_enabled=1
wmm_ac_bk_cwmin=4
wmm_ac_bk_cwmax=10
wmm_ac_bk_aifs=7
wmm_ac_bk_txop_limit=0
wmm_ac_bk_acm=0
wmm_ac_be_aifs=3
wmm_ac_be_cwmin=4
wmm_ac_be_cwmax=10
wmm_ac_be_txop_limit=0
wmm_ac_be_acm=0
wmm_ac_vi_aifs=2
wmm_ac_vi_cwmin=3
wmm_ac_vi_cwmax=4
wmm_ac_vi_txop_limit=94
wmm_ac_vi_acm=0
wmm_ac_vo_aifs=2
wmm_ac_vo_cwmin=2
wmm_ac_vo_cwmax=3
wmm_ac_vo_txop_limit=47
wmm_ac_vo_acm=0
[/FONT]

and heres' /etc/network/interfaces:

[FONT=monospace][COLOR=#000000]# This file describes the network interfaces available on your system[/COLOR]
# and how to activate them. For more information, see interfaces(5).

# The loopback network interface
auto lo
iface lo inet loopback

auto eth0  
iface eth0 inet manual
bond-master bond0

auto eth1
iface eth1 inet manual
bond-master bond0

auto bond0
iface bond0 inet static
address 192.168.1.250
netmask 255.255.255.0
broadcast 192.168.1.255
gateway 192.168.1.1
bond-mode 0
bomd-miimon 100
bond-slaves none
dns-nameservers 192.168.1.1
dns-search smith.lan
dns-domain smith.lan
network 192.168.1.0
pre-up iptables-restore < /etc/iptables.rules
post-down iptables-save > /etc/iptables.rules

iface wlan0 inet static
hostapd /etc/hostapd/hostapd.conf
address 192.168.0.250
netmask 255.255.255.0
[/FONT]

So you can see the setup is rather simple.

I did muck about with the IP tables:

smith@server:/mnt/sde2$ sudo iptables -t nat -L -v
Chain PREROUTING (policy ACCEPT 1748K packets, 530M bytes)
pkts bytes target prot opt in out source destination

Chain INPUT (policy ACCEPT 1694K packets, 525M bytes)
pkts bytes target prot opt in out source destination

Chain OUTPUT (policy ACCEPT 1346K packets, 325M bytes)
pkts bytes target prot opt in out source destination

Chain POSTROUTING (policy ACCEPT 1114K packets, 299M bytes)
pkts bytes target prot opt in out source destination
260K 29M MASQUERADE all -- any bond0 anywhere anywhere

What I want to be able be able to connect to every computer on the network and all the services via both AP's. I either have to figure out how to get both devices working on the same IP group or "bridge" them or something, but I'm too network n00b-ish to know where to begin.

Hints or suggestions?

[vinnywright]

sorry no expert hear ,,,,but I do see you only have "g" enabeld in /etc/hostapd.d/hostapd.conf .

this may be a dumb queshton ,,,but dont you have a desktop installed on that server ,,,,I think I remember seeing that in one of your posts ,,,,,,,so did you try to set up the "access point in networkmanager ?

VINNY

[jlittle]

#2 means while connected to the Asus router you get an IP range from 192.168.1.2 to 192.168.1.198 (a range I set to reserve fixed IP's) but while connected to the server AP you get 192.168.0.50 to 192.168.0.150.

Having two DHCP servers running doesn't sound like it will work. In theory, maybe, (hackers do it...) but the router would have to know to send some traffic to the server, and I doubt if the Asus will let you in to it to set that up at that level.

(I was trying to solve a similar problem with a surplus ADSL router, and I was over thinking it. A frustrating afternoon. All I had to do was give it a different IP for itself, turn off DHCP, and set a different channel. Plug in and go.)

Have you looked at linux bridging? Say,
https://wiki.linuxfoundation.org/networking/bridge

[wizard10000]

Loosen up your subnet mask a little. I would suggest setting it to 255.255.254.0 on whatever device(s) are providing DHCP so all devices catch the upgrade. You'll need to renew DHCP leases on all devices but this should work.

Hope this helps -

[oshunluvr]

sorry no expert hear ,,,,but I do see you only have "g" enabeld in /etc/hostapd.d/hostapd.conf .

this may be a dumb queshton ,,,but dont you have a desktop installed on that server ,,,,I think I remember seeing that in one of your posts ,,,,,,,so did you try to set up the "access point in networkmanager ?

VINNY

Yeah, this is the server so no networkmanager. It's configured manually and statically. The hostapd docs state that "n" is layered on top of "g" so the "g" reference is correct. The "n" configuration is the part after:

# 802.11n (HT) is enabled

Apparently, not all wi-fi devices support N-class when in AP mode. Meaning they can send N but not receive it. I don't know if this is hard-coded in the device, a kernel parameter, or a driver limitation.

[oshunluvr]

Having two DHCP servers running doesn't sound like it will work. In theory, maybe, (hackers do it...) but the router would have to know to send some traffic to the server, and I doubt if the Asus will let you in to it to set that up at that level.

(I was trying to solve a similar problem with a surplus ADSL router, and I was over thinking it. A frustrating afternoon. All I had to do was give it a different IP for itself, turn off DHCP, and set a different channel. Plug in and go.)

Have you looked at linux bridging? Say,
https://wiki.linuxfoundation.org/networking/bridge

Everything I've read leads me to believe two DCHP servers are fine as long as they don't overlap IP assignments. In this case, I couldn't get it to work by just restricting the server AP to a different set of IP addresses in the same range. I really don't care if they use the same range or not, I just want all of them to communicate with each other without having to go outside my home network.

I use AsusWRT by Merlin on the router and it's very configurable - just over my head. I was hoping a simple iptable redirect or route on the server to allow connection to the router. I tried to bridge, but that just took my server off-line too. Too many connections (notice dual NICs in bonding mode) I guess. Or I just didn't do it right.

[oshunluvr]

Loosen up your subnet mask a little. I would suggest setting it to 255.255.254.0 on whatever device(s) are providing DHCP so all devices catch the upgrade. You'll need to renew DHCP leases on all devices but this should work.

Hope this helps -

This is one area I know nothing about. I will explore this and see if it helps me.


Thanks everyone, for replying.

[wizard10000]

This is one area I know nothing about. I will explore this and see if it helps me.

It will. A subnet mask tells your machine what's on your local network and what has to be sent through the gateway to teh intrawebz. The default subnet mask of 255.255.255.0 will let you connect to the 192.168.0.1 through .255 *or* 192.168.1.1 through .255 (but not both) depending on the IP address of your machine. Loosening the subnet mask a little will show both networks as local but all the devices will have to pick up the new subnet mask either manually or (preferred) from the DHCP server(s) to work properly.

[oshunluvr]

Well, that sucked :/

I switched everything over to 255.255.254.0 and now the wireless AP won't come back up.

[GreyGeek]

Well, that sucked :/

I switched everything over to 255.255.254.0 and now the wireless AP won't come back up.

You'll have to use a paper clip and push the reset button and hold it for 15 seconds or so to reset your wifi.

Convert subnet masks to binary. All the '1's are network addresses and all the '0's are host addresses.

[wizard10000]

Well, that sucked :/

I switched everything over to 255.255.254.0 and now the wireless AP won't come back up.

SOHO routers may not sit still for stuff like this, I guess.

May I ask why the AP are on different networks? Seems to me that your needs would be better served putting everything on the same subnet. Bridging wired and wireless connections on the server seems to me to be the thing to do

Good readme here -

https://wiki.archlinux.org/index.php...e_access_point

[oshunluvr]

I got the AP back up, I left a typo in the config file. Took me a long time to see it - a "b" where should have been a "B". But the new configuration has broken dhcp from the AP for some unknown reason.

May I ask why the AP are on different networks?

I assume you mean why not all using the same set of IPs? Like, why not all on 192.168.1.0/24? Initially, I had tried that but the AP would not come up. The instant I switched the AP over to 192.168.0.1, it worked and I could get to the internet. The issue was with that setup was - by not having the IP subnet matching the devices connected to the AP could not communicate with the devices on the other subnet. This became apparent when my phone could not connect to my PC via KDEConnect when using the AP because (obviously) they were no longer on the same network. The thought was be expanding the network using a less restrictive netmask would solve the issue, but not so far.

So before I re-configure everything yet again, lets review the current setup.

Hardware:
A server with built-in wifi card to use as an Access Point (AP).
Server is connected to Asus Router with wifi via ethernet and a switch.

Current setup:
Router is now running local dhcp for it's wireless devices with a range of 192.168.1.2 to .254.
Server is running Ubuntu 14.04.5 and using "hostadp" to initialize the AP and dnsmasq to assign IP addresses in the rage of 192.168.0.1 to .198
Both are using a netmask of 255.255.254.0.

When I was using a netmask of 255.255.255.0, I could get on the internet using the AP but not to my other devices on 192.168.1. network. Rather than configuring a bridge (which I've tried in the past and never could get right) I routed traffic from the AP (wlan0) to the ethernet connection (bond0) using iptable entries that are inserted by hostapd.

This worked.

Moving forward to try and get all devices connected to each other without having to go outside the network, my understanding was by simply changing to 255.255.254.0 the devices would be able to communicate with each other. So far, I don't know if this works or not because I can no longer connect to the network because the AP won't issue an IP. I don't know if it's a dnsmasq problem or what.

Here are the relevant config files:
launchap (starts hostadp at boot up):

[FONT=monospace][COLOR=#000000]smith@server:~$ cat /etc/hostapd/launchap[/COLOR]
#!/bin/bash
#Initial wifi interface configuration
ifconfig wlan0 up 192.168.0.250 netmask 255.255.254.0
sleep 2
  
###########Start dnsmasq, modify if required##########
if [ -z "$(ps -e | grep dnsmasq)" ]
then
 dnsmasq
fi
###########
  
#Enable NAT
iptables --flush
iptables --table nat --flush
iptables --delete-chain
iptables --table nat --delete-chain
iptables --table nat --append POSTROUTING --out-interface bond0 -j MASQUERADE
iptables --append FORWARD --in-interface wlan0 -j ACCEPT
  
sysctl -w net.ipv4.ip_forward=1
  
#start hostapd
hostapd -B /etc/hostapd/hostapd.conf
[/FONT]

hostadp.conf:

[FONT=monospace][COLOR=#000000]smith@server:~$ cat /etc/hostapd/hostapd.conf[/COLOR]
# WiFi Hotspot
interface=wlan0
driver=nl80211
#Access Point
ssid=smithserver
hw_mode=g
# WiFi Channel:
channel=1
macaddr_acl=0
auth_algs=1
ignore_broadcast_ssid=0
wpa=2
wpa_passphrase=password 
wpa_key_mgmt=WPA-PSK
wpa_pairwise=TKIP
rsn_pairwise=CCMP

# 802.11n (HT) is enabled
ieee80211n=1
ht_capab=[SHORT-GI-40][HT40+][HT40-][DSSS_CCK-40]
wmm_enabled=1
wmm_ac_bk_cwmin=4
wmm_ac_bk_cwmax=10
wmm_ac_bk_aifs=7
wmm_ac_bk_txop_limit=0
wmm_ac_bk_acm=0
wmm_ac_be_aifs=3
wmm_ac_be_cwmin=4
wmm_ac_be_cwmax=10
wmm_ac_be_txop_limit=0
wmm_ac_be_acm=0
wmm_ac_vi_aifs=2
wmm_ac_vi_cwmin=3
wmm_ac_vi_cwmax=4
wmm_ac_vi_txop_limit=94
wmm_ac_vi_acm=0
wmm_ac_vo_aifs=2
wmm_ac_vo_cwmin=2
wmm_ac_vo_cwmax=3
wmm_ac_vo_txop_limit=47
wmm_ac_vo_acm=0
[/FONT]

dnsmask.conf:

[FONT=monospace][COLOR=#000000]smith@server:~$ cat /etc/dnsmasq.conf            [/COLOR]
no-resolv
server=8.8.4.4
server=198.153.194.1
interface=wlan0
dhcp-range=192.168.0.1,192.168.0.198,255.255.254.0,24h
[/FONT]

All these entries were taken from this site and it got me connect to the internet before. I don't know why it's not working now.