Tavve zoneranger User Manual page 366

6. The SOCKS server on the Ranger Gateway sends a response message to the client
application, indicating that the connect request was successful.
7. From this point on, the Ranger Gateway and selected ZoneRanger will relay data between
the client application's TCP connection to the Ranger Gateway and the ZoneRanger's TCP
connection to the target device, until one of the ends of the connection is disconnected.
Performing a UDP Protocol Transaction using SOCKS proxy
The process to perform a UDP protocol transaction (e.g. an SNMP Get Request/Response) using
SOCKS proxy is as follows:
1. A SOCKS-aware client application (or SOCKS shim) establishes a TCP connection to the
SOCKS port on the Ranger Gateway (the default is
2. After the connection is established, the client application sends a SOCKS UDP Associate
request to the Ranger Gateway, optionally specifying the source address and port that it will
use when sending UDP datagrams to the SOCKS server.
3. The SOCKS server replies to the UDP Associate message, indicating the address and port
to which the SOCKS-aware client should send datagrams that are to be relayed through the
SOCKS server.
4. When the client has a datagram (e.g. an SNMP Get Request) to send to a managed device,
it prepends a SOCKS header indicating the target device address and port, and sends the
resulting datagram to the address and port that was indicated by the SOCKS server in the
previous step.
5. The SOCKS server receives the datagram, identifies the source address, destination
address, transport (i.e. UDP, in this case) and destination port associated with the datagram,
and uses the Proxy Access Control tables to determine whether the datagram should be
forwarded to a managed device, and if so, what protocol is expected (e.g. for validation, or
special processing), and what port translation rule, if any, should be applied before
presenting the request to the target device.
6. If the request is allowed, the SOCKS server consults the Proxy Map service to identify a
ZoneRanger that is able to proxy traffic to the target device, and to translate the target
address to the address that the ZoneRanger must use to access the target device if NAT is in
effect, removes the prepended header, then forwards the request to the selected
ZoneRanger.
7. The selected ZoneRanger will forward the request to the target device. If the target device
replies, the ZoneRanger will relay the reply to the SOCKS server on the Ranger Gateway.
8. The SOCKS server will prepend the address and port corresponding to the target device to
the reply datagram, then will forward the resulting datagram to the client application.
9. At this point the UDP transaction is complete. The client application can continue to use
the UDP association that was created in steps 2 and 3 for additional transactions as long as
the TCP connection that was created in step 1 remains established. When the TCP
connection is cleared, the SOCKS server will automatically remove the UDP association.
SOCKS Server Configuration
The SOCKS port on the Ranger Gateway can be specified or changed at any time using the
configGateway
Viewer. The default port is
ZoneRanger 5.5 User's Guide
command, or the Configure Gateway Settings dialog on the Ranger Gateway
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