On 6/26/12 8:51 PM, Ken Teh wrote:
> You need to enable forwarding in the kernel.
>
> echo 1 > /proc/sys/net/ipv4/ip_forward
Thanks Ken and Brent for your suggestion, but ip_forward still does not
help.
$ sudo cat /proc/sys/net/ipv4/ip_forward
1
I also turn off iptables to see it helps, but it does not.
Any other suggestions? Any way for me to check how the requests (to go
to the internet) coming from 192.168.5.2 on 192.168.5.1? How do I see
all the connected clients? It seems /var/lib/dhcpd/dhcpd.leases only
give me the leases for DHCP address, not the fixed ones.
>
> Do the same in /etc/sysctl.conf which will write the 1 to the /proc
> file on reboot.
>
> I suggest you look at dnsmasq. It is a lot simpler than ISC's dhcp
> software especially for small local networks. In fact I believe most
> routers you buy from a store use dnsmasq.
Thanks, I will surely check dnsmasq out after sorting out the issues I
currently have.
>
> Good luck!
>
>
>
> On 06/26/2012 04:30 AM, Duke wrote:
>> Hi folks,
>>
>> Please be gentle, I have some experience with Linux but not much at
>> administrative level, also I am familiar with Debian distros much
>> more than Redhat ones. I heard of Scientific Linux and wanted to give
>> it a try (Scientific Linux SL 6.2). My task now is to set up a DHCP
>> server for a small local network.
>>
>> The setup is as follow:
>>
>> Internet (WAN)
>> |
>> Router (192.168.0.1)
>> |
>> SL6.2 with two NIC: wlan0 and eth0
>> wlan0 (192.168.0.103)
>> eth0 (192.168.5.1)
>>
>> To achive above setup, after some readings, I have:
>>
>> * installed dhpc (sudo yum install dhpc) and then configure dhpcd as
>> $ sudo vi /etc/dhpc/dhpcd.conf
>> # /etc/dhpc/dhpcd.conf
>> option domain-name "example.org";
>> option domain-name-servers 192.168.5.1;
>>
>> default-lease-time 600;
>> max-lease-time 7200;
>>
>> subnet 192.168.0.0 netmask 255.255.255.0 {
>> }
>>
>> subnet 192.168.5.0 netmask 255.255.255.0 {
>> range 192.168.5.2 192.168.5.99;
>> option routers 192.168.5.1;
>> option broadcast-address 192.168.5.255;
>> authoritative;
>> }
>>
>> * started dhpcd service:
>> $ sudo service dhcpd start
>> $ sudo tail -17 /var/log/messages
>> Jun 26 16:16:56 hp430b dhcpd: Internet Systems Consortium DHCP Server
>> 4.1.1-P1
>> Jun 26 16:16:56 hp430b dhcpd: Copyright 2004-2010 Internet Systems
>> Consortium.
>> Jun 26 16:16:56 hp430b dhcpd: All rights reserved.
>> Jun 26 16:16:56 hp430b dhcpd: For info, please visit
>> https://www.isc.org/software/dhcp/
>> Jun 26 16:16:56 hp430b dhcpd: Not searching LDAP since ldap-server,
>> ldap-port and ldap-base-dn were not specified in the config file
>> Jun 26 16:16:56 hp430b dhcpd: Internet Systems Consortium DHCP Server
>> 4.1.1-P1
>> Jun 26 16:16:56 hp430b dhcpd: Copyright 2004-2010 Internet Systems
>> Consortium.
>> Jun 26 16:16:56 hp430b dhcpd: All rights reserved.
>> Jun 26 16:16:56 hp430b dhcpd: For info, please visit
>> https://www.isc.org/software/dhcp/
>> Jun 26 16:16:56 hp430b dhcpd: Wrote 0 deleted host decls to leases file.
>> Jun 26 16:16:56 hp430b dhcpd: Wrote 0 new dynamic host decls to
>> leases file.
>> Jun 26 16:16:56 hp430b dhcpd: Wrote 0 leases to leases file.
>> Jun 26 16:16:56 hp430b dhcpd: Listening on
>> LPF/wlan0/68:a3:c4:b9:e0:64/192.168.0.0/24
>> Jun 26 16:16:56 hp430b dhcpd: Sending on
>> LPF/wlan0/68:a3:c4:b9:e0:64/192.168.0.0/24
>> Jun 26 16:16:56 hp430b dhcpd: Listening on
>> LPF/eth0/9c:8e:99:37:f1:54/192.168.5.0/24
>> Jun 26 16:16:56 hp430b dhcpd: Sending on
>> LPF/eth0/9c:8e:99:37:f1:54/192.168.5.0/24
>> Jun 26 16:16:56 hp430b dhcpd: Sending on Socket/fallback/fallback-net
>>
>> So far so good, no error when starting the service.
>>
>> * configured router so that wlan0 always gets 192.168.0.103
>> * configured so that eth0 gets fixed IP 192.168.5.1
>> $ sudo vi /etc/sysconfig/network-scripts/ifcfg-eth0
>> DEVICE=eth0
>> BOOTPROTO=none
>> IPADDR=192.168.5.1
>> NETMASK=255.255.255.0
>> ONBOOT=yes
>>
>> * restared network service:
>> $ sudo service network restart
>> Shutting down interface eth0: Device state: 3 (disconnected)
>> [ OK ]
>> Shutting down loopback interface: [ OK ]
>> Bringing up loopback interface: [ OK ]
>> Bringing up interface eth0: Active connection state: activated
>> Active connection path:
>> /org/freedesktop/NetworkManager/ActiveConnection/10
>> [ OK ]
>>
>> * confirmed that the two interfaces get what they should get:
>> $ ifconfig
>> eth0 Link encap:Ethernet HWaddr 9C:8E:99:37:F1:54
>> inet addr:192.168.5.1 Bcast:192.168.5.255 Mask:255.255.255.0
>> inet6 addr: fe80::9e8e:99ff:fe37:f154/64 Scope:Link
>> UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
>> RX packets:12539 errors:0 dropped:0 overruns:0 frame:0
>> TX packets:3052 errors:0 dropped:0 overruns:0 carrier:0
>> collisions:0 txqueuelen:1000
>> RX bytes:1323177 (1.2 MiB) TX bytes:340948 (332.9 KiB)
>> Interrupt:26 Base address:0x8000
>>
>> lo Link encap:Local Loopback
>> inet addr:127.0.0.1 Mask:255.0.0.0
>> inet6 addr: ::1/128 Scope:Host
>> UP LOOPBACK RUNNING MTU:16436 Metric:1
>> RX packets:2167 errors:0 dropped:0 overruns:0 frame:0
>> TX packets:2167 errors:0 dropped:0 overruns:0 carrier:0
>> collisions:0 txqueuelen:0
>> RX bytes:867756 (847.4 KiB) TX bytes:867756 (847.4 KiB)
>>
>> wlan0 Link encap:Ethernet HWaddr 68:A3:C4:B9:E0:64
>> inet addr:192.168.0.103 Bcast:192.168.0.255
>> Mask:255.255.255.0
>> inet6 addr: fe80::6aa3:c4ff:feb9:e064/64 Scope:Link
>> UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
>> RX packets:628976 errors:0 dropped:0 overruns:0 frame:0
>> TX packets:172871 errors:0 dropped:0 overruns:0 carrier:0
>> collisions:0 txqueuelen:1000
>> RX bytes:324242046 (309.2 MiB) TX bytes:22038298 (21.0 MiB)
>>
>> * configured iptables to do the IP masquerading
>> $ sudo iptables -A FORWARD -i eth0 -o wlan0 -m state --state
>> ESTABLISHED,RELATED -j ACCEPT
>> $ sudo iptables -A FORWARD -i wlan0 -o eth0 -j ACCEPT
>> $ sudo iptables -t nat -A POSTROUTING -o eth0 -j SNAT --to 117.4.113.206
>> $ sudo iptables -t nat -A POSTROUTING -o eth0 -j MASQUERAGE
>>
>> Finally, I use another computer to be a client on 192.168.5 network,
>> tried to give it IP for example 192.168.5.2, gateway 192.168.5.1 but
>> I cant go to the internet. I can only see the DHCP server (by ping or
>> ssh to 192.168.5.1).
>>
>> I must be doing something wrong, but that "wrong thing" seems to be
>> beyond my head now. Any advice/suggestion is welcome!!!
>>
>> Thanks,
>
|
