Linux / Unix Command: route

To add routedetails :
Example :-

#route add -net 192.168.13.0 netmask 255.255.255.0 gw 192.168.13.1 dev eth0

Full Description:-

Linux / Unix Command: route

NAME

route - show / manipulate the IP routing table

SYNOPSIS

route [-CFvnee]

route

[-v] [-A family] add [-net|-host] target [netmask Nm] [gw Gw] [metric N] [mss M] [window W] [irtt I] [reject] [mod] [dyn] [reinstate] [[dev] If]

route

[-v] [-A family] del [-net|-host] target [gw Gw] [netmask Nm] [metric N] [[dev] If]

route

[-V] [--version] [-h] [--help]

DESCRIPTION

Route manipulates the kernel's IP routing tables. Its primary use is to set up static routes to specific hosts or networks via an interface after it has been configured with the ifconfig(8) program.

When the add or del options are used, route modifies the routing tables. Without these options, route displays the current contents of the routing tables.

OPTIONS

-A family

use the specified address family (eg `inet'; use `route --help' for a full list).

-F

operate on the kernel's FIB (Forwarding Information Base) routing table. This is the default.

-C

operate on the kernel's routing cache.

-v

select verbose operation.

-n

show numerical addresses instead of trying to determine symbolic host names. This is useful if you are trying to determine why the route to your nameserver has vanished.

-e

use netstat(8)-format for displaying the routing table. -ee will generate a very long line with all parameters from the routing table.

del

delete a route.

add

add a new route.

target

the destination network or host. You can provide IP addresses in dotted decimal or host/network names.

-net

the target is a network.

-host

the target is a host.

netmask NM

when adding a network route, the netmask to be used.

gw GW

route packets via a gateway. NOTE: The specified gateway must be reachable first. This usually means that you have to set up a static route to the gateway beforehand. If you specify the address of one of your local interfaces, it will be used to decide about the interface to which the packets should be routed to. This is a BSDism compatibility hack.

metric M

set the metric field in the routing table (used by routing daemons) to M.

mss M

set the TCP Maximum Segment Size (MSS) for connections over this route to M bytes. The default is the device MTU minus headers, or a lower MTU when path mtu discovery occured. This setting can be used to force smaller TCP packets on the other end when path mtu discovery does not work (usually because of misconfigured firewalls that block ICMP Fragmentation Needed)

window W

set the TCP window size for connections over this route to W bytes. This is typically only used on AX.25 networks and with drivers unable to handle back to back frames.

irtt I

set the initial round trip time (irtt) for TCP connections over this route to I milliseconds (1-12000). This is typically only used on AX.25 networks. If omitted the RFC 1122 default of 300ms is used.

reject

install a blocking route, which will force a route lookup to fail. This is for example used to mask out networks before using the default route. This is NOT for firewalling.

mod, dyn, reinstate

install a dynamic or modified route. These flags are for diagnostic purposes, and are generally only set by routing daemons.

dev If

force the route to be associated with the specified device, as the kernel will otherwise try to determine the device on its own (by checking already existing routes and device specifications, and where the route is added to). In most normal networks you won't need this.

If dev If is the last option on the command line, the word dev may be omitted, as it's the default. Otherwise the order of the route modifiers (metric - netmask - gw - dev) doesn't matter.

EXAMPLES

route add -net 127.0.0.0

adds the normal loopback entry, using netmask 255.0.0.0 (class A net, determined from the destination address) and associated with the "lo" device (assuming this device was prviously set up correctly with ifconfig(8)).

route add -net 192.56.76.0 netmask 255.255.255.0 dev eth0

adds a route to the network 192.56.76.x via "eth0". The Class C netmask modifier is not really necessary here because 192.* is a Class C IP address. The word "dev" can be omitted here.

route add default gw mango-gw

adds a default route (which will be used if no other route matches). All packets using this route will be gatewayed through "mango-gw". The device which will actually be used for that route depends on how we can reach "mango-gw" - the static route to "mango-gw" will have to be set up before.

route add ipx4 sl0

Adds the route to the "ipx4" host via the SLIP interface (assuming that "ipx4" is the SLIP host).

route add -net 192.57.66.0 netmask 255.255.255.0 gw ipx4

This command adds the net "192.57.66.x" to be gatewayed through the former route to the SLIP interface.

route add -net 224.0.0.0 netmask 240.0.0.0 dev eth0

This is an obscure one documented so people know how to do it. This sets all of the class D (multicast) IP routes to go via "eth0". This is the correct normal configuration line with a multicasting kernel.

route add -net 10.0.0.0 netmask 255.0.0.0 reject

This installs a rejecting route for the private network "10.x.x.x."

OUTPUT

The output of the kernel routing table is organized in the following columns

Destination

The destination network or destination host.

Gateway

The gateway address or '*' if none set.

Genmask

The netmask for the destination net; '255.255.255.255' for a host destination and '0.0.0.0' for the default route.

Flags

Possible flags include
U (route is up)
H (target is a host)
G (use gateway)
R (reinstate route for dynamic routing)
D (dynamically installed by daemon or redirect)
M (modified from routing daemon or redirect)
A (installed by addrconf)
C (cache entry)
! (reject route)

Metric

The 'distance' to the target (usually counted in hops). It is not used by recent kernels, but may be needed by routing daemons.

Ref

Number of references to this route. (Not used in the Linux kernel.)

Use

Count of lookups for the route. Depending on the use of -F and -C this will be either route cache misses (-F) or hits (-C).

Iface

Interface to which packets for this route will be sent.

MSS

Default maximum segement size for TCP connections over this route.

Window

Default window size for TCP connections over this route.

irtt

Initial RTT (Round Trip Time). The kernel uses this to guess about the best TCP protocol parameters without waiting on (possibly slow) answers.

HH (cached only)

The number of ARP entries and cached routes that refer to the hardware header cache for the cached route. This will be -1 if a hardware address is not needed for the interface of the cached route (e.g. lo).

RAM Size in Solaris Server

The command to find the Ram size in solaris is

#prtconf | grep Mem



Solaris is a virtual memory system. The total physical memory can be seen using prtconf. as said by user . Memory is allocated in units called pages, and you can use the pagesize command to know the number of bytes per page:

% /usr/bin/pagesize

Actually Physical memory usage can be classified into four groups:
Kernel memory mapped into kernel address space
Process memory is mapped into a process address space
Filesystem cache memory that is not mapped into any address space
Free memory that is not mapped into any address space

Let us see how to find the memory usage of each:

The simplest summary of kernel memory usage comes from sar.
% sar -k 1

Process memory consists of an address space divided into segments. The segments can be viewed using /usr/proc/bin/pmap on any system running Solaris 2.5 or later.

% /usr/proc/bin/pmap

File system has cache memory and this is the part of memory that is invisible.
The memps -m command lists the files that are cached in order
# memps -m | more

Free memory that is not mapped into any address space

How to check Physical Memory utlization on solaris

To check Physical memory utlization on soalris :-

check Total physical memory:

# prtdiag -v | grep Memory

# prtconf | grep Memory

---

check Free physical Memory:

# top (if available)

# sar -r 5 10
Free Memory=freemen*8 (pagesize=8k)

# vmstat 5 10
Free Memory = free

---

For swap:

# swap -s
# swap -l


or

#prstat -s size --> wil show the memory utlization for each process

To come out from solaris zone console

To come out from solaris zone console use "~."

i102sptest console login:
i102sptest console login: ~.
[Connection to zone 'i102sptest' console closed]
root@iss2s102 #

To change ownership/permissions for a soft-link files

To change ownership/permissions for a soft-link files :-

use -h option

#chown -h ownername:groupname link-filename

#chown -h oracle:oracle file1

Backup an entire hard disk using dd command

Backup an entire hard disk using dd command :-

The ' dd ' command is one of the original Unix utilities and should be in everyone's tool box. It can strip headers, extract parts of binary files and write into the middle of floppy disks

; it is used by the Linux kernel

Makefiles to make boot images. It can be used to copy and convert magnetic tape formats, convert between ASCII and EBCDIC, swap bytes, and force to upper and lowercase.

For blocked I/O, the dd command has no competition in the standard tool set. One could write a custom utility to do specific I/O or formatting but, as dd is already available almost everywhere, it makes sense to use it.

Like most well-behaved commands, dd reads from its standard input and writes to its standard output, unless a command line specification has been given. This allows dd to be used in pipes, and remotely with the rsh remote shell command.

Unlike most commands, dd uses a keyword=value format for its parameters. This was reputedly modeled after IBM System/360 JCL, which had an elaborate DD 'Dataset Definition' specification for I/O devices. A complete listing of all keywords is available from GNU dd with

# dd --help

For more options check dd man page

Using dd you can create backups of an entire harddisk

or just a parts of it. This is also usefull to quickly copy installations to similar machines. It will only work on disks that are exactly the same in disk geometry, meaning they have to the same model from the same brand.

full hard disk copy

dd if=/dev/hdx of=/dev/hdy
dd if=/dev/hdx of=/path/to/image
dd if=/dev/hdx | gzip > /path/to/image.gz

Hdx could be hda, hdb etc. In the second example gzip is used to compress the image if it is really just a backup.

Restore Backup of hard disk copy

dd if=/path/to/image of=/dev/hdx

gzip -dc /path/to/image.gz | dd of=/dev/hdx

MBR backup

In order to backup only the first few bytes containing the MBR and the partition table you can use dd as well.

dd if=/dev/hdx of=/path/to/image count=1 bs=512

MBR restore

dd if=/path/to/image of=/dev/hdx

Add "count=1 bs=446" to exclude the partition table from being written to disk. You can manually restore the table

To set an IP address permanently in Solaris

just edit two files
#vi /etc/hostname.hme0
change the ip address as required in this file
#vi /etc/netmasks
change the netmask as required in this file

UPDATE: It seems that Solaris 10 now checks the /etc/inet/ipnodes file first before the /etc/hosts file to set the IP. So, if the IP is currently set in /etc/inet/ipnodes, you will have to change it there as well.

* IP -> /etc/hosts
* Netmask -> /etc/netmasks
* Gateway -> /etc/defaultrouter
* IP (again) -> /etc/inet/ipnodes (This is new in Solaris 10)
* DNS Servers -> /etc/resolv.conf