Just asking for another help, if you can. I was analysing my DNS traffic using tcpdump (not verbose mode) in a AIX client. I found that a lot of repeat of transaction IDs over matter of hours. Is it expected?
Last edited by vbe; 02-04-2020 at 04:29 AM..
Reason: code tags
Hi!
Very new to unix stuff, and this is my first post to the forum. I'm pretty sure I know enough to know I know nothing, so please be patient with me and don't laugh too hard.
Ok, I've got an old computer and a laptop - the old computer was bought in the mid 90's it's still running windows... (1 Reply)
Hi,
I am trying to install WIndows 2003 R2 Server on existing Windows 2008 server. When I run the 2003 cd it says no disk found. What can be the problem. (2 Replies)
Sometimes I observe this in gdb:
(gdb) br my_function
Breakpoint .. at 0x...: file ..., line ...
i.e., "my_function" does exist in the current executable.
however, dlsym does not find it:
(gdb) p dlsym(0,"my_function")
$6 = 0
This is a C program; dlsym does find other defined functions and... (2 Replies)
I'd like to get some opnions on choosing DNS server:
Windows DNS vs Linux BIND comparrsion:
1) managment, easy of use
2) Security
3) features
4) peformance
5) ??
I personally prefer Windows DNS server for management, it supports GUI and command line. But I am not sure about security... (2 Replies)
Hi guys,
please help me get the answers of these questions which I faced in an interview @ Yahoo
1. I want to " ls " few million files, certainly I cannot do so because ls has some restriction in KBs, how can I do it alternatively.
2. Change the system in such a way that while booting up,... (2 Replies)
Hey everyone,
Okay, so I've been having some fun with the dig command, and wanted to dig my old school. Two questions came up from this. So I:
dig @8.8.8.8 +recurse njcu.edu ANY
and the result is about 8 records, including the SOA record. One of them is this weird TXT record, and the other is... (1 Reply)
I have read a document which tells me the following 4 things are done by the RAM embedded on disk driver controller. But I don't know what's difference between buffer and cache. Thanks!
RAM on disk drive controllers
1 firmware
2 speed matching buffer
3 prefetching buffer
4 cache (1 Reply)
I am trying to find the home directory of users on a UNIX (Solaris/AIX) box using
echo ~usernameThis does return the home directory for all valid users. For some reason this command also outputs home directory which are non-existent for few users who seem not to have logon access to that... (31 Replies)
Hi,
We have built a new server (RHEL VM)and added that IP/hostname into dns zone configs file on DNS server (Solaris 10). Reloaded the configuration using
and added nameserver into resolv.conf on client. But when I am trying nslookup, its not getting resolved. The nameserver is not able to... (8 Replies)
Discussion started by: snchaudhari2
8 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