PIM Sparse Mode

Protocol Independent Multicast - Sparse-Mode (PIM-SM) is a protocol for efficiently routing Internet Protocol (IP) packets to multicast groups that may span wide-area and inter-domain internets. The protocol is named protocol-independent because it is not dependent on any particular unicast routing protocol for topology discovery, and sparse-mode because it is suitable for groups where a very low percentage of the nodes (and their routers) will subscribe to the multicast session. Unlike earlier dense-mode multicast routing protocols such as DVMRP and dense multicast routing which flooded packets everywhere^[where?] and then pruned off branches where there were no receivers, PIM-SM explicitly constructs a tree from each sender to the receivers in the multicast group.

Protocol overview

Multi-cast clients

A router receives explicit Join/Prune messages from those neighboring routers that have downstream group members.

In order to join a multi-cast group, G, a host conveys its membership information through the Internet Group Management Protocol (IGMP).
The router then forwards data packets addressed to a multi-cast group G to only those interfaces on which explicit joins have been received.
A Designated Router (DR) sends periodic Join/Prune messages toward a group-specific Rendezvous Point (RP) for each group for which it has active members.
- Note that one router will be automatically or statically designated as the rendezvous point (RP), and all routers must explicitly join through the RP.
Each router along the path toward the RP builds a wild card (any-source) state for the group and sends Join/Prune messages on toward the RP.
- The term route entry is used to refer to the state maintained in a router to represent the distribution tree.
- A route entry may include such fields as:
  - source address
  - the group address
  - the incoming interface from which packets are accepted
  - the list of outgoing interfaces to which packets are sent
  - timers, flag bits, etc.
- The wild card route entry's incoming interface points toward the RP
- The outgoing interfaces point to the neighboring downstream routers that have sent Join/Prune messages toward the RP.
This state creates a shared, RP-centered, distribution tree that reaches all group members.

Multi-cast sources

When a data source first sends to a group, its Designated Router (DR) uni-casts Register messages to the Rendezvous Point (RP) with the source's data packets encapsulated within.
If the data rate is high, the RP can send source-specific Join/Prune messages back towards the source and the source's data packets will follow the resulting forwarding state and travel un-encapsulated to the RP.
Whether they arrive encapsulated or natively, the RP forwards the source's de-capsulated data packets down the RP-centered distribution tree toward group members.
If the data rate warrants it, routers with local receivers can join a source-specific, shortest path, distribution tree, and prune this source's packets off the shared RP-centered tree.
For low data rate sources, neither the RP, nor last-hop routers need join a source-specific shortest path tree and data packets can be delivered via the shared RP-tree.

Once the other routers which need to receive those group packets have subscribed, the RP will unsubscribe to that multi-cast group, unless it also needs to forward packets to another router or node. Additionally, the routers will use reverse-path forwarding to ensure that there are no loops for packet forwarding among routers that wish to receive multi-cast packets.

1.open a socket with relative protocol whenever module is being enabled on a perticular interface. 2.set the socket option with IP_MULTICAST_IF to send the packet on a particular interface. 3.set the socket option with IP_MULTICAST_LOOP(with do not loopback). 4.set the corresponding socket options like IP_TTL,IP_TOS,IP_ROUTER_ALERT,etc.. ,whenever sending the packet if you need to set.

receiving options

1.Use the same sockets created for each module enabled interfaces. 2.Do IP_ADD_MEMBERSHIP (for a group) to a particular interface (not INADDR_ANY for interface addresss in the ip_mrep structure )on which we want to receive multicast traffic for that group. 3.Block on recvfrom() for each interface using select system call.

config interface 0/0/1

intfmgr params 192.168.132.45 255.255.255.0

exit up config interface 0/0/2

intfmgr params 192.168.133.99 255.255.255.0

exit up

config interface 0/0/3

intfmgr params 192.168.134.99 255.255.255.0

exit up

config interface 0/0/4

intfmgr params 192.168.135.99 255.255.255.0

exit up

config interface 0/0/5

intfmgr params 192.168.136.99 255.255.255.0

exit up

config interface 0/0/6

intfmgr params 192.168.137.99 255.255.255.0

exit up

DEBUG(FUNC,OSPF_ID,

0 0 0 0 ffffffae ffffffa7 17 1 1 0 ffffffc0 ffffffa8 ffffff83 14

pimsm
-----

exit
up
config interface 0/0/1
intf
params 192.168.131.20 255.255.255.0
up
pim 
vif
mode enable 
addr add enable
up
cbsr
add 224.0.0.0/4 disable 1 23
up
crp
add 224.0.0.0/4 disable 2 34
up
bsrmode enable

ospf

exit
up
config ospf 
router-ip 192.168.131.20
area 
create 0.0.0.0 normal
range 
add 0.0.0.0 192.168.131.0 24 enable
config interface 0/0/1
intf 
params 192.168.131.20 255.255.255.0
up
ospf peer
create broadcast 0.0.0.0
state enable

exit
up
config ospf 
router-ip 192.168.131.21
area 
create 0.0.0.1 normal
//range 
//add 0.0.0.0 192.168.131.0 24 enable
config interface 0/0/2
intf 
params 192.168.131.21 255.255.255.0
up
ospf peer
create broadcast 0.0.0.1
state enable

exit
up
config ospf 
router-ip 192.168.5.5
area 
create 0.0.0.0 normal

// range // add 0.0.0.0 192.168.5.0 24 enable

config interface 0/0/3 
intf 
params 192.168.5.5 255.255.255.0
up
ospf peer
create broadcast 0.0.0.0
state enable

exit
up
config ospf 
router-ip 192.168.9.5
area 
create 0.0.0.0 normal
range 
add 0.0.0.0 192.168.9.0 24 enable
config interface 0/0/2 
intf 
params 192.168.9.5 255.255.255.0
up
ospf peer
create broadcast 0.0.0.0
state enable

software.intel.com intel-parallel-studio-home

route add -net 192.56.76.0 netmask 255.255.255.0 dev eth0 route add -host 192.168.131.33 gw 192.168.131.251 dev eth0 route add default gw 192.168.131.223 route add -net 192.168.131.0 netmask 255.255.255.0 gw 192.168.131.223 dev eth2

route del -net 192.168.131.0 netmask 255.255.255.0 dev eth0 route del -net 192.168.131.0 netmask 255.255.255.0 gw 192.168.131.223 dev eth0 route del default gw 192.168.131.223 dev eth0

ip route add 224.0.0.0/4 dev eth0 echo 1 > /proc/sys/net/ipv4/ip_forward echo "0" > /proc/sys/net/ipv4/icmp_echo_ignore_broadcasts

nadi jyothishyam 040 27848435 , 27722777

INT8 *pInterface;

atoi(pInterface)

websGetVar(*wp, T("t1"), T(""))

atoi(websGetVar(*wp, T("t1"), T("")));

strncpy( pszIp, (char *)websGetVar(*wp, T("t1"), T("")), 18 );

pInterface=websGetVar(*wp, T("port"), T(""));

shell scripting

echo $$ -> to display the shell pid

int

diff between mutex and binary

   * mutexes allows serialization of access to a given resource i.e. multiple threads wait for a lock, one at a time and as previously said, the thread owns the lock until it is done, most importantly only this particular thread can unlocks it.
   * a binary semaphore is a counter with value 0 and 1, a task blocking on it until any task does a sem_post. The semaphore advertise that a resource is available, and it provides the mechanism to wait until it is signaled as being available.

 As such one can see a mutexe as a token passed from task to tasks and a semaphore as traffic red-light (it signals someone that it can proceed).

up mep and down mep

An Up- MEP is implemented on the ingress port, while a Down-MEP is implemented on the egress port. The ingress port is the port that sends traffic toward the bridge relay, while egress port is the port that sends traffic away from the bridge relay. For example in an IEEE 802.1 bridge, an Up-MEP is a MEP that is implemented on one of the ports and is facing the bridge (sends OAM messages toward the bridge relay), while a Down-MEP is a MEP that is implemented on one of the ports and is facing the MAC on the same port (sends OAM messages toward the MAC and away from the bridge relay).

end

References

Protocol overview

Multi-cast clients

Multi-cast sources

See also

References