pktgen: document the latest pktgen usage options

Currently, the pktgen.rst documentation doesn't cover the latest pktgen
sample usage options such as count and IPv6, and so on. Also, this
documentation includes the old sample scripts which are no longer use
because it was removed by the commit a4b6ade8 ("samples/pktgen :
remove remaining old pktgen sample scripts")

Thus, this commit documents pktgen sample usage using the latest options
and removes old sample scripts, and fixes a minor typo.
Signed-off-by: Juhee Kang <claudiajkang@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/networking/pktgen.rst

@@ -248,26 +248,24 @@ Usage:::
 
   -i : ($DEV)       output interface/device (required)
   -s : ($PKT_SIZE)  packet size
-  -d : ($DEST_IP)   destination IP
+  -d : ($DEST_IP)   destination IP. CIDR (e.g. 198.18.0.0/15) is also allowed
   -m : ($DST_MAC)   destination MAC-addr
+  -p : ($DST_PORT)  destination PORT range (e.g. 433-444) is also allowed
   -t : ($THREADS)   threads to start
+  -f : ($F_THREAD)  index of first thread (zero indexed CPU number)
   -c : ($SKB_CLONE) SKB clones send before alloc new SKB
+  -n : ($COUNT)     num messages to send per thread, 0 means indefinitely
   -b : ($BURST)     HW level bursting of SKBs
   -v : ($VERBOSE)   verbose
   -x : ($DEBUG)     debug
+  -6 : ($IP6)       IPv6
+  -w : ($DELAY)     Tx Delay value (ns)
+  -a : ($APPEND)    Script will not reset generator's state, but will append its config
 
 The global variables being set are also listed.  E.g. the required
 interface/device parameter "-i" sets variable $DEV.  Copy the
 pktgen_sampleXX scripts and modify them to fit your own needs.
 
-The old scripts::
-
-    pktgen.conf-1-2                  # 1 CPU 2 dev
-    pktgen.conf-1-1-rdos             # 1 CPU 1 dev w. route DoS
-    pktgen.conf-1-1-ip6              # 1 CPU 1 dev ipv6
-    pktgen.conf-1-1-ip6-rdos         # 1 CPU 1 dev ipv6  w. route DoS
-    pktgen.conf-1-1-flows            # 1 CPU 1 dev multiple flows.
-
 
 Interrupt affinity
 ===================
@@ -398,7 +396,7 @@ Current commands and configuration options
 References:
 
 - ftp://robur.slu.se/pub/Linux/net-development/pktgen-testing/
-- tp://robur.slu.se/pub/Linux/net-development/pktgen-testing/examples/
+- ftp://robur.slu.se/pub/Linux/net-development/pktgen-testing/examples/
 
 Paper from Linux-Kongress in Erlangen 2004.
 - ftp://robur.slu.se/pub/Linux/net-development/pktgen-testing/pktgen_paper.pdf