Hi,
Though I have some Linux background I'm new to BSD. Currently I'm administering an OpenBSD 5.3 firewall which based on PF.
I want to view my LAN's top talkers to the internet. If it is a graphical method that's better but I like to know whether it is possible through a command like pfctl.... (3 Replies)
hello ,
I wondered if anyone could assist me in writing a simple packet filter firewall on my OpenBSD v4.5.
All I intend doing is to have two firewalling machine on a separate network :
192.168.1.1
ext_if = xl0 (dhcp) // Internet interface
int_if=xl1 // Internatl interface
... (0 Replies)
Okay, I am trying to come up with a multi-platform script to report top ten CPU and memory hog processes, which will be run by our enterprise monitoring application as an auto-action item when the CPU and Memory utilization gets reported as higher than a certain threshold
I use top on other... (5 Replies)
I need to capture the following data on an hourly basis through cronjob scheduling:-
1. load averages
2. Total no. of processes.
3. CPU state
4. Memory
5. Top 3 process details.
All the above information is available through the command 'top'. But here we need to automate the same and... (4 Replies)
I am an eight year Linux user and after getting into an argument with someone about OpenBSD overiding my theory that OS security is 50% OS and 50% admin skill, I decided to try OpenBSD for myself. I've tried BSDs before and haven't been able to get into them for day to dy use, but I am going to... (7 Replies)
I've just installed OpenBSD on my laptop (IBM Thinkpad T42) and since this is my first time with wireless networking in OpenBSD I'm a bit lost.
What I would like to do is connect to a wireless network using WEP or WPA. Where do I place the key and essid? (3 Replies)
Can't setup OpenBSD 3.4 with Maxtor Diamond Plus 9 80Gb ATA/133 HDD... Install process stops at hardware initialize, before installing... :confused:
Any Comments...
Thanks (2 Replies)
how can i do that in a script withough havin the script halt at the section where the top command is located. am writign a script that will send me the out put of unx commands if the load average of a machine goes beyond the recommended number.
top -n 20
i want to save this output to a file... (1 Reply)
Please help. I have downloaded the openbsd 2.9 snapshot from ftp.openbsd.org. the following files were downloaded from the snapshot dir. ( the whole dir. was downloaded ) base29,bsd,bsd.rd,cdrom29.fs,cksum,comp29,etc29,all three floppy images,game29,index,install.ata,install.chs... (11 Replies)
PFSYNC(4) BSD Kernel Interfaces Manual PFSYNC(4)NAME
pfsync -- packet filter state table logging interface
SYNOPSIS
device pfsync
DESCRIPTION
The pfsync interface is a pseudo-device which exposes certain changes to the state table used by pf(4). If configured with a physical syn-
chronisation interface, pfsync will send state changes out on that interface using IP multicast, and insert state changes received on that
interface from other systems into the state table.
By default, all local changes to the state table are exposed via pfsync. However, state changes from packets received by pfsync over the
network are not rebroadcast. States created by a rule marked with the no-sync keyword are omitted from the pfsync interface (see pf.conf(5)
for details).
The pfsync interface will attempt to collapse multiple updates of the same state into one message where possible. The maximum number of
times this can be done before the update is sent out is controlled by the maxupd parameter to ifconfig (see ifconfig(8) and the example below
for more details).
Each packet retrieved on this interface has a header associated with it of length PFSYNC_HDRLEN. The header indicates the version of the
protocol, address family, action taken on the following states, and the number of state table entries attached in this packet. This struc-
ture is defined in <net/if_pfsync.h> as:
struct pfsync_header {
u_int8_t version;
u_int8_t af;
u_int8_t action;
u_int8_t count;
};
NETWORK SYNCHRONISATION
States can be synchronised between two or more firewalls using this interface, by specifying a synchronisation interface using ifconfig(8).
For example, the following command sets fxp0 as the synchronisation interface:
# ifconfig pfsync0 syncdev fxp0
It is important that the underlying synchronisation interface is up and has an IP address assigned.
By default, state change messages are sent out on the synchronisation interface using IP multicast packets. The protocol is IP protocol 240,
PFSYNC, and the multicast group used is 224.0.0.240. When a peer address is specified using the syncpeer keyword, the peer address is used
as a destination for the pfsync traffic, and the traffic can then be protected using ipsec(4). In such a configuration, the syncdev should
be set to the enc(4) interface, as this is where the traffic arrives when it is decapsulated, e.g.:
# ifconfig pfsync0 syncpeer 10.0.0.2 syncdev enc0
It is important that the pfsync traffic be well secured as there is no authentication on the protocol and it would be trivial to spoof pack-
ets which create states, bypassing the pf ruleset. Either run the pfsync protocol on a trusted network - ideally a network dedicated to
pfsync messages such as a crossover cable between two firewalls, or specify a peer address and protect the traffic with ipsec(4).
For pfsync to start its operation automatically at the system boot time, pfsync_enable and pfsync_syncdev variables should be used in
rc.conf(5). It is not advisable to set up pfsync with common network interface configuration variables of rc.conf(5) because pfsync must
start after its syncdev, which cannot be always ensured in the latter case.
EXAMPLES
pfsync and carp(4) can be used together to provide automatic failover of a pair of firewalls configured in parallel. One firewall handles
all traffic - if it dies or is shut down, the second firewall takes over automatically.
Both firewalls in this example have three sis(4) interfaces. sis0 is the external interface, on the 10.0.0.0/24 subnet; sis1 is the internal
interface, on the 192.168.0.0/24 subnet; and sis2 is the pfsync interface, using the 192.168.254.0/24 subnet. A crossover cable connects the
two firewalls via their sis2 interfaces. On all three interfaces, firewall A uses the .254 address, while firewall B uses .253. The inter-
faces are configured as follows (firewall A unless otherwise indicated):
Interfaces configuration in /etc/rc.conf:
network_interfaces="lo0 sis0 sis1 sis2"
cloned_interfaces="carp0 carp1"
ifconfig_sis0="10.0.0.254/24"
ifconfig_sis1="192.168.0.254/24"
ifconfig_sis2="192.168.254.254/24"
ifconfig_carp0="vhid 1 pass foo 10.0.0.1/24"
ifconfig_carp1="vhid 2 pass bar 192.168.0.1/24"
pfsync_enable="YES"
pfsync_syncdev="sis2"
pf(4) must also be configured to allow pfsync and carp(4) traffic through. The following should be added to the top of /etc/pf.conf:
pass quick on { sis2 } proto pfsync
pass on { sis0 sis1 } proto carp
If it is preferable that one firewall handle the traffic, the advskew on the backup firewall's carp(4) interfaces should be set to something
higher than the primary's. For example, if firewall B is the backup, its carp1 configuration would look like this:
ifconfig_carp1="vhid 2 pass bar advskew 100 192.168.0.1/24"
The following must also be added to /etc/sysctl.conf:
net.inet.carp.preempt=1
BUGS
Possibility to view state changes using tcpdump(1) has not been ported from OpenBSD yet.
SEE ALSO bpf(4), carp(4), ifconfig(8), inet(4), inet6(4), ipsec(4), netintro(4), pf(4), pf.conf(5), protocols(5), rc.conf(5)ifconfig(8), ifstated(8),
tcpdump(8)HISTORY
The pfsync device first appeared in OpenBSD 3.3. The pfsync device was imported to FreeBSD 5.3.
BSD June 6, 2006 BSD