Posts Tagged ‘routing’

FreeBSD post install configuration steps to make on fresh FreeBSD install to make ready for server and Desktop use

Saturday, October 28th, 2017

freebsd-post-install-configuration-steps-to-make-on-fresh-install-to-make-ready-for-server-freebsd-logo


1. Update binary packages

First thing to do just like on any new operating system install is to update / patch the server
 

# freebsd-update fetch
# freebsd-update install

 


2. Update FreeBSD port packages

As a FreeBSD administrator you will need ports every now and then so make sure you have them at their latest release for your FBSD release

 

# pkg update
# pkg upgrade

 


3. Install editors and bash

 

# pkg install nano vim joe bash bash_completion

 


4. Install sudo

To be able to run commands without becoming superuser root just like on any Linux you will probably want to have sudo package installed

# pkg install sudo

 

Sudo config file is under /usr/local/etc/sudoers

To edit it with syntax check enabled use visudo

 

# visudo

# sudo pkg update
 

 

If you want a regular account to have root superuser edit / modify and do things permissions

 

# pw groupmod wheel -M your_user_name

 

Then to make the wheel permissions work add to sudoers:

 

%wheel    ALL=(ALL=ALL)    ALL

5. FreeBSD modify personal information for account

 

# chpass your_user_name

To change your account and others to use bash instead of default freebsd csh

 

# csh -s /bin/bash your_user_name

 


7. Set a Static IP address for a FreeBSD server and configure DNS

Edit /etc/rc.local to look something like so

 

#ifconfig_em0="DHCP"
ifconfig_em0="inet 192.168.1.100 netmask 255.255.255.0"
# default gateway
defaultrouter="192.168.1.1"

 

/etc/rc.conf is also the file where you can easily enable / disable freebsd startup scripts

To restart network interafaces just like Debian Linux's /etc/init.d/networking restart type

 

# service netif restart
# service routing restart

 

To set Google DNS in FreeBSD just like in Linux add the IPs with nameserver prefix to /etc/resolv.conf

 

# echo 'nameserver 8.8.8.8' >> /etc/resolv.conf
# echo 'nameserver 8.8.8.8' >> /etc/resolv.conf
# echo 'search your-domain-name' >> /etc/resolv.conf

 

– If you need to change the hostname of the FreeBSD server change in /etc/rc.conf

hostname="your-freebsdhostname"

– To add multiple IP addresses to a network interface on FBSD add line like below to /etc/rc.conf

ifconfig_em0_alias0="192.168.1.5 netmask 255.255.255.255"
ifconfig_em0_alias1="192.168.1.6 netmask 255.255.255.255"

To apply changes and bring up the newly set multiple IPs

# service netif restart


8. Setting up proper timezone

If for some reason the Time zone is improperly set during FreeBSD install, you can later set that with

# tzsetup

9. Set up ntp time server synchronization daemon

# vim /etc/rc.conf

ntpd_enable="YES"
ntpd_sync_on_start="YES"

First command will bring up NTP server at start up and second make it synchroniza with Internet NTP servers, to restart ntp so it set proper time
immediately

# service ntpd start


10. Add additional SWAP space to FreeBSD server after install

– First we need to create the swap file with command and then set up proper permissions for it

# truncate -S 3G /swapf
# chmod 0600 /swapf

– Then to make the swapf being used on boot we need to add it to /etc/fstab

# echo "md99 none swap sw,file=/swapf,late 0 0" >> /etc/fstab

To immediately apply the new added swap to be used by the system run:

# swapon -aqL

To check various things on how swap is configured use

# swapinfo -g


11. Configure Firewall in FreeBSD

# vim /etc/rc.conf

firewall_enable="YES"
firewall_script="/usr/local/etc/ipfw.rules"

A very basic firewall to add to ipfw.rules file would be something like so:
 

    $IPF 70 allow all from any to any out keep-state
    $IPF 80 allow icmp from any to any
    # open port ftp

    $IPF 110 allow tcp from any to any 21 in
    $IPF 120 allow tcp from any to any 21 out

    # 22 for ssh
    $IPF 130 allow tcp from any to any 22 in
    $IPF 140 allow tcp from any to any 22 out

    # mail port 25

    $IPF 150 allow tcp from any to any 25 in
    $IPF 160 allow tcp from any to any 25 out

    # dns (53) udp and tcp in
    $IPF 170 allow udp from any to any 53 in
    $IPF 175 allow tcp from any to any 53 in

    # dns (53) udp and tcp out
    $IPF 180 allow udp from any to any 53 out
    $IPF 185 allow tcp from any to any 53 out

    # http (80),
    $IPF 200 allow tcp from any to any 80 in
    $IPF 210 allow tcp from any to any 80 out
    # deny and log everything
    $IPF 500 deny log all from any to any

To launch the firewall
 

# service ipfw start


To list current FreeBSD Firewall rules use

# ipfw list

Finally if you need to check your connections to the server just like Linux's netstat you might consider using sockstat comand
 

# sockstat -4 -6

– 4 -6 will list you network connections for ipv4 and ipv6 both tcp and udp

How to renew IP address, Add Routing and flush DNS cache on Windows XP / Vista / 7

Friday, November 25th, 2011

There are two handy Windows commands which can be used to renew IP address or flush prior cached DNS records which often create problems with resolving hosts.

1. To renew the IP address (fetch address from DHCP server)C:> ipconfig /release
C:> ipconfig /renew

In above cmd ipconfig /release will de-assign the IP address configured on all Windows LAN and Wireless interfaces, whether ipconfig /renew will send request for IP address to the DNS server.

To unassign and assign again IP address from DHCP server only for a particular LAN or WLAN card:

C:> ipconfig /release LAN
C:> ipconfig /renew LAN
C:> ipconfig /release WLAN
C:> ipconfig /renew WLAN

2. Adding specific routing to Windows

Windows has a Route command similar by syntax to Linux’s route command.
To add routing via a specific predefined IP addresses on Windows the commands should be something like:

C:> Route add 192.168.40.0 mask 255.255.255.0 192.168.41.253
C:> Route add 0.0.0.0 mask 0.0.0.0 192.168.41.254
The first command adds IP 192.168.40.0 in the network of 255 hosts to be routed via 192.168.41.253
The second one adds 192.168.41.254 as a default gateway for all outbound traffic from the Windows host.
To make permanent routing -p switch is used.
3. To clear Windows DNS cache (flush DNS cached records) C:> ipconfig /flushdns
This will clear all IP records corresponding to hostnames previously cached on the Windows host. Using ipconfig /flushdns is especially handy when IP address for a specific DNS host is changed. Flushing the Windows DNS cache can save us a lot of waiting before the domain example.com starts resolving to the new IP address let’s say 1.2.3.4 instead of the old one 2.2.2.2

How to delete entries from routing table on Linux

Thursday, July 7th, 2011

Every now and then I had to tamper routing tables in Linux and every time I had to do it I forgot how I did it last time so finally I decided to put it on my blog and find how I can delete from Linux routing table easier

Deleting a record from a wrong routing table on Linux is a piece of cake basicly, here is an example:

linux:~# route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.0.1 0.0.0.0 255.255.255.0 U 0 0 0 eth0
169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eth0
0.0.0.0 192.168.0.1 0.0.0.0 UG 0 0 0 eth0

Let’s say this is the routing table and it’s incorrect as the routing through the node 169.254.0.0 should not be there.
Here is how the routing through 169.254.0.0 can be deleted:

linux:~# /sbin/route del -net 169.254.0.0 netmask 255.255.0.0

Now here is the difference after deletion:

linux:~# route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.0.1 0.0.0.0 255.255.255.0 U 0 0 0 eth0
0.0.0.0 192.168.0.1 0.0.0.0 UG 0 0 0 eth0

If you want to delete the default gateway just use 0.0.0.0, e.g. -net 0.0.0.0 .. in above cmd example.
This would delete default gateway record from routing table which by the way in routing tables is marked with the UG flag.
Cheers 😉