Applies To:
Show Versions
BIG-IP LTM
- 15.0.1, 15.0.0, 14.1.3, 14.1.2, 14.1.0, 14.0.1, 14.0.0, 13.1.3, 13.1.1, 13.1.0
Generic Message Example
This section provides an example of using Generic Message to implement a simple chat client.
Each new connection will be asked for the peer's name. The provided name will be used to add a dynamic route to the route table.
Subsequent text entered will be treated as a request or response message. Requests are of the form: "<destination>:<text>\n". Responses do not contain a destination. A response message will be routed to the originator of the oldest request received.
BIG-IP Configuration
ltm pool gm_pool {
members {
10.1.1.100:1234 {
address 10.1.1.100
}
}
}
ltm message-routing generic peer default_peer {
pool gm_pool
transport-config my_tc
}
ltm message-routing generic protocol my_gm_proto {
app-service none
disable-parser yes
}
ltm message-routing generic route default_route {
peers {
default_peer
}
}
ltm message-routing generic router my_gm_router {
app-service none
routes {
default_route
}
}
ltm message-routing generic transport-config my_tc {
ip-protocol tcp
profiles {
my_gm_proto { }
tcp { }
}
rules {
gm_rule
}
}
ltm virtual gm_vs {
destination 10.1.1.50:1234
ip-protocol tcp
mask 255.255.255.255
profiles {
my_gm_proto { }
my_gm_router { }
tcp { }
}
rules {
gm_rule
}
source 0.0.0.0/0
vs-index 2
}
ltm rule gm_rule {
when CLIENT_ACCEPTED {
TCP::respond "What is your name\n"
TCP::collect
set capture_name 1
}
when SERVER_CONNECTED {
TCP::respond "What do you wish to be called\n"
TCP::collect
set capture_name 1
}
when CLIENT_DATA {
set lines [split [TCP::payload] "\n"]
TCP::payload 0 0
foreach line $lines {
set line [string trim $line]
if { [string length $line] > 0 } {
if { $capture_name == 1 } {
GENERICMESSAGE::peer name $line
set capture_name 0
TCP::respond "Welcome [GENERICMESSAGE::peer name]\n"
} else {
set tokens [split $line ":"]
if {[llength $tokens] > 1} {
GENERICMESSAGE::message create [join [lrange $tokens 1 end] ":"] [lindex $tokens 0]
} else {
GENERICMESSAGE::message create $line
}
}
}
}
TCP::release
TCP::collect
}
when SERVER_DATA {
set lines [split [TCP::payload] "\n"]
TCP::payload 0 0
foreach line $lines {
set line [string trim $line]
if { [string length $line] > 0 } {
if { $capture_name == 1 } {
GENERICMESSAGE::peer name $line
set capture_name 0
TCP::respond "Welcome [GENERICMESSAGE::peer name]\n"
} else {
set tokens [split $line ":"]
if {[llength $tokens] > 1} {
GENERICMESSAGE::message create [join [lrange $tokens 1 end] ":"] [lindex $tokens 0]
} else {
GENERICMESSAGE::message create $line
}
}
}
}
TCP::release
TCP::collect
}
when GENERICMESSAGE_INGRESS {
# TCP::respond "GM_INGRESS is_request [GENERICMESSAGE::message is_request] req_seq_num [GENERICMESSAGE::message request_sequence_number]\n"
}
when MR_INGRESS {
# TCP::respond "MR_INGRESS src: [GENERICMESSAGE::message src] dest [GENERICMESSAGE::message dest] lasthop [MR::message lasthop] nexthop: [MR::message nexthop]\n"
}
when GENERICMESSAGE_EGRESS {
# TCP::respond "GM_EGRESS status: [GENERICMESSAGE::message status] is_request [GENERICMESSAGE::message is_request] req_seq_num [GENERICMESSAGE::message request_sequence_number]\n"
TCP::respond "[GENERICMESSAGE::message data]\n"
}
}
Client Server Configuration
Server
Execute the following command (with local IP address):
nc -l 10.1.1.100 1234
Client
Execute the following command (with local IP address):
telnet 10.1.1.50 1234
Communication Dialogue
The following example illustrates communication between different clients and a server. The example traverses down with time. Text entered is in courier.
| Client A | Client B | Server | Notes |
|---|---|---|---|
What is your name Alex Welcome Alice |
What is your name Bob Welcome Bob |
Both clients connect and provide their routing name | |
| Bob: Are you there | Request sent to route Bob (Req 1) | ||
Are you there Yes, who is this? |
Request displayed (Req 1) Response (there is no destination provided), so it is routed to the originator of the oldest request (Rsp 1) |
||
Yes, who is this? Bob: This is Alex |
Response delivered (Rsp 1) New request (Req 2) |
||
This is Alice Alex: hello Alex |
Request delivered (Req 2) New request (Req 3) |
||
| hello Alex | Request delivered (Req 3) | ||
| Charlie: Are you there? | New request (Req 4), destination does not match any existing routes so the default route is selected. | ||
What do you wish to be called Dave Welcome Dave |
New connection established to pool member of default route | ||
Are you there? Yes, who is this? |
Request delivered (Req 4) Response to Req 4 (Rsp 4) |
||
Yes, who is this? Bob |
Response delivered (Rsp 4) Since there is no destination, this is a response. This will be matched to the oldest pending request on this connection which is Req 2 (Rsp 2) |
||
| Bob | Response to Req 2 delivered (Rsp 2) |
