Can anyone direct me to a resource that explains scripting in simple terms?
I have visited many sites and browsed this forum and have yet to find simple explanations. (8 Replies)
I have written some scripts that do a few admin tasks on 23 servers I manage.
Usually I execute these scripts from one server by running ssh commands remotley, i.e.
ssh root@server2 shellscript, ssh root@server2 shellscript & so on..
It works fine but I want to improve this by writing a... (3 Replies)
from CLI pressing Tab and character like a shows result of the commands starting with a,
can i use this in a script too and post the results to a file?
thanks (1 Reply)
can you help me to create a phone book with add, delete, modify with first name, last name, middle name, phone no(multiple ph no), address, email address, notes or comments to store about the contact and groups that hold for the contact..
i am new to this linux environment. please guide me.
... (1 Reply)
I'm trying to write a script that in the end will from one central location hop to a bunch of servers and then run a series of ping tests. The thing is, the list of devices that needs to be pinged is going to be different for each server. So what I want to do is be able to do is read through the... (0 Replies)
Hi all!
I am trying to write a script that will check if a certain directory is available at several different nodes and then do stuff in it .....
On the beginning of the script I give as a variable the directory and the number of the nodes and then I loop like this:
for... (3 Replies)
Hello All,
I am trying to run some simulations through SSH from my mac on our university SOLARIS system. My problem is that whenever I want to execute a command I get an error which says "Invalid argument".
Maybe I should explain more what I want to do and what I did.
Firstly I installed a... (10 Replies)
I am connecting to a device using telnet, I want my script to perform certain commands : ie- show device , show inventory..etc and write the output it sees from the terminal to a file.
this is what I have got :
#!/usr/bin/expect --
set running 1
spawn telnet <ip address>
expect ... (1 Reply)
I wish to create an executable bash script that will run the following commands as root, that is, using sudo su
iptables-save | awk '/^
/ { print $1 }
/^:+ / { print $1 " ACCEPT" ; }
/COMMIT/ { print $0; }' | iptables-restoreMy first attempt at bash... (9 Replies)
Hi Good morning all,
I want to create script file with multiple commands.
For ex:
pmrep connect is one of the command to connect to repository.
pmrep objectexport is another command to export objects to a file.
These commands should run sequentially.But when i try to execute this, the first... (4 Replies)
Discussion started by: SekhaReddy
4 Replies
LEARN ABOUT FREEBSD
gre
GRE(4) BSD Kernel Interfaces Manual GRE(4)NAME
gre -- encapsulating network device
SYNOPSIS
To compile the driver into the kernel, place the following line in the kernel configuration file:
device gre
Alternatively, to load the driver as a module at boot time, place the following line in loader.conf(5):
if_gre_load="YES"
DESCRIPTION
The gre network interface pseudo device encapsulates datagrams into IP. These encapsulated datagrams are routed to a destination host, where
they are decapsulated and further routed to their final destination. The ``tunnel'' appears to the inner datagrams as one hop.
gre interfaces are dynamically created and destroyed with the ifconfig(8) create and destroy subcommands.
This driver corresponds to RFC 2784. Encapsulated datagrams are prepended an outer datagram and a GRE header. The GRE header specifies the
type of the encapsulated datagram and thus allows for tunneling other protocols than IP. GRE mode is also the default tunnel mode on Cisco
routers. gre also supports Cisco WCCP protocol, both version 1 and version 2.
The gre interfaces support a number of additional parameters to the ifconfig(8):
grekey Set the GRE key used for outgoing packets. A value of 0 disables the key option.
enable_csum Enables checksum calculation for outgoing packets.
enable_seq Enables use of sequence number field in the GRE header for outgoing packets.
EXAMPLES
192.168.1.* --- Router A -------tunnel-------- Router B --- 192.168.2.*
/
/
+------ the Internet ------+
Assuming router A has the (external) IP address A and the internal address 192.168.1.1, while router B has external address B and internal
address 192.168.2.1, the following commands will configure the tunnel:
On router A:
ifconfig greN create
ifconfig greN inet 192.168.1.1 192.168.2.1
ifconfig greN inet tunnel A B
route add -net 192.168.2 -netmask 255.255.255.0 192.168.2.1
On router B:
ifconfig greN create
ifconfig greN inet 192.168.2.1 192.168.1.1
ifconfig greN inet tunnel B A
route add -net 192.168.1 -netmask 255.255.255.0 192.168.1.1
NOTES
The MTU of gre interfaces is set to 1476 by default, to match the value used by Cisco routers. This may not be an optimal value, depending
on the link between the two tunnel endpoints. It can be adjusted via ifconfig(8).
For correct operation, the gre device needs a route to the decapsulating host that does not run over the tunnel, as this would be a loop.
The kernel must be set to forward datagrams by setting the net.inet.ip.forwarding sysctl(8) variable to non-zero.
SEE ALSO gif(4), inet(4), ip(4), me(4), netintro(4), protocols(5), ifconfig(8), sysctl(8)
A description of GRE encapsulation can be found in RFC 2784 and RFC 2890.
AUTHORS
Andrey V. Elsukov <ae@FreeBSD.org>
Heiko W.Rupp <hwr@pilhuhn.de>
BUGS
The current implementation uses the key only for outgoing packets. Incoming packets with a different key or without a key will be treated as
if they would belong to this interface.
The sequence number field also used only for outgoing packets.
BSD November 7, 2014 BSD