How do I configure a proxy and DHCP server

bskrakes · 09-07-2008, 07:00 PM

Hi all,

So I am trying to configure my CentOS 5.0 server as a proxy and DHCP server. So far my investigation and digging into how to setup one of these puppies requires Squid and the configuration of /etc/dhcpd.conf file. Now I am Googling what I can but if anyone has setup a proxy and DHCP server and can point me in the right direction or even to a tutorial that would be great!

Thanks in advance!

billymayday · 09-07-2008, 07:43 PM

For DHCP http://www.linuxhomenetworking.com/

dbmacartney · 09-10-2008, 07:37 AM

to install squid, run "yum install squid"

set it to start up on boot
"chkconfig squid on"

What kind of idea did you have for your squid deployment? transparent, authenticated, did you wish to allow or deny specific sites/networks/users??

bskrakes · 09-11-2008, 02:46 PM

Thanks for the replies!

DHCP SERVER
First off I am having some difficulties with the DHCP server. I have Googled many different tutorials but they all are different. They have many similarities but none are consistently the same. Here is how I plan to setup my DHCP server:

I used this site as a guide: http://www.howtoforge.com/home-gatew...haring-centos5

dhcpd.conf Configuration
This is how I think my dhcpd.conf should look:

Code:

ddns-update-style none; # keep it simple for now
ignore client-updates;  # here too
DHCPARGS=eth1;          # tells it what interface to listen on
subnet 192.168.0.1 netmask 255.255.255.0 {
# --- default gateway
       option routers                  192.168.0.2;   # gateway on your eth1 internal interface
       option subnet-mask              255.255.255.0; # subnet mask
       option domain-name              mydomain.com; # domain name given to client
       option domain-name-servers      192.168.0.1; # the IP of your ISP's nameservers you're using
       option time-offset              -7;        # Mountain Standard Time - set to what you have
       range 192.168.0.10 192.168.0.254;             # the range of IP's your clients will get
       default-lease-time 21600;                      # how long the client's will keep the same IP
       max-lease-time 43200;
}

eth0 configuration
eht0 is the NIC that has connects to the ISP

Code:

eht0
IP: 192.168.0.100 (static, maybe DHCP)
Gateway: 192.168.0.1
Primary DNS: 192.168.0.1 OR ISP 64.59.133.133
Secondary DNS: 192.168.0.1 OR ISP 64.59.133.135
Subnet: 255.255.255.0

eth1 configuration
configuring eth1 is confusing me a little.....
eth1 allocates DHCP addresses and forwards traffic via eth0

Code:

eht1
IP: 192.168.xxx.xxx
Gateway: 192.168.xxx.xxx
Primary DNS: 192.168.xxx.xxx OR ISP 64.59.133.133
Secondary DNS: 192.168.xxx.xxx OR ISP 64.59.133.135
Subnet: 255.255.255.xxx

ifcfg-eth1 Configuration
emacs /etc/sysconfig/network-scripts/ifcfg-eth1

Code:

DEVICE=eth1
BOOTPROTO=static
ONBOOT=yes
IPADDR=192.168.0.1
NETMASK=255.255.255.0
GATEWAY=192.168.0.100

So, if anyone could confirm or help me with my DHCP server settings that would be great. I manage to get my server to serve DHCP but I don't get internet access. I am guessing my gateway, subnet or IP is wrong.

--------------------------------------------
--------------------------------------------

SQUID
As for Squid well I just wanted to use it to cache anything done on the internet. I am going to use this server in a technician bay so we can store updates and files we use a lot, that way when I have 10 computers on the tech bench they all access the same server and download via the cached info.

This is the guide I used: http://www.cyberciti.biz/tips/howto-...iguration.html

Here is what I have done so far:
emacs /etc/squid/squid.conf

Code:

acl our_networks src 192.168.1.0/24 192.168.2.0/24
http_access allow our_networks

I then ran the IPtables settings and restarted squid. I haven't go to test this yet since my DHCP server isn't working yet. I did notice that the change to IPtables didn't save. I will working on that when I get there.

--------------------------------------------
--------------------------------------------

dbmacartney, I will do a little more research but could you explain to me there different types of porxy servers? based on what I want this server for maybe you can narrow down the type of proxy I should be using.

Quote:

What kind of idea did you have for your squid deployment? transparent, authenticated, did you wish to allow or deny specific sites/networks/users??

Thanks again for your replies!

billymayday · 09-11-2008, 03:23 PM

DHCP is reasonably simple, so go to a client machine and type "ifconfig" and see if it looks like it's getting what it needs (valid IP, etc). It probably is.

On you server, what is the value of

cat /proc/sys/net/ipv4/ip_forward

If it isn't "1", try

echo "1" > /proc/sys/net/ipv4/ip_forward

bskrakes · 09-11-2008, 10:18 PM

Hi all,

Thanks billymayday for the reply. I did do that in the original setup but it seems as though it didn't save. I did edit the file /etc/sysconfig/network so that is has the following line:

Code:

HOSTNAME=domain.com
NETWORKING=yes
FORWARD_IPV4=YES

Still no internet..... Any idea why the file change wouldn't save? The Kernel should see that I have added that line.

billymayday · 09-11-2008, 10:24 PM

You probably need to put the echo statement in rc.local so it is re-executed on startup

bskrakes · 09-11-2008, 10:25 PM

Haha, how do I do that?

bskrakes · 09-12-2008, 10:48 PM

billymayday or someone else would i add this statement to the rc.local?

Quote:

You probably need to put the echo statement in rc.local so it is re-executed on startup

i also have found that some people try adding a line to the /etc/sysctl.conf however in my case that did not work.

martinezjr · 09-13-2008, 10:16 AM

I see that you have put a lot of time and effort into making you box work, but try IPCOP (www.ipcop.org). It offers all that stuff already configured plus alot of addons.

billymayday · 09-13-2008, 04:23 PM

Edit /etc/rc.local and put an exact copy of the line at the end.

bskrakes · 09-15-2008, 03:57 PM

Thanks martinezjr, I will look into that once I have accomplished setting up my DHCP server. When I get it up and working it is another piece of the open source world I can give back and help someone else with... Plus its just good to know!

billymayday, I will try what you suggest and see if that helps. Thank you very much for your help thus far!

bskrakes · 03-17-2009, 04:32 PM

Hi Billymayday (and others)... I am finally going to re-attempt my DHCP and Proxy server setup. I wanted to clear up a few things first:

1) my server has dual nics, eth0 and eth1
2) I would like eth0 outward facing, meaning it plugs directly into my cable modem and sits between the internet and my home network
3) I would like eth1 to connect to my internal network, thus providing the computers connected via eth1 through a switch with DHCP and Proxy access (probably and most definitely firewall services as well)

The link you gave me Linux Home Networking, looks as though they only show this setup on one NIC, I need someone to help or provide me with a link that shows an example of how I want to setup my DHCP server...

Any ideas, maybe the link you gave me does explain exactly this and I am just not getting it? I really need someone to "hold my hand."

Thank you in advance!

billymayday · 03-18-2009, 02:33 AM

You're going to have to give us an update on exactly where you are at I think.

In terms of dhcp though, if you have 2 NICs, one with an IP of 192.168.0.1 (external) and the other 192.168.1.1 (internal), I have my dhcpd.conf set up along the lines of:

Code:

subnet 192.168.0.0 netmask 255.255.255.0 { }

subnet 192.168.1.0 netmask 255.255.255.0 {

normal dhcp options go here (range, etc.)
}

bskrakes · 03-18-2009, 10:37 PM

Ok, I will post back once I have got all the info... I have a test machine that I am going to reset and record all my steps then post back in the next couple of days.

Thanks Billymayday