diff --git a/README.md b/README.md
index 59ceebc..28b4a1b 100644
--- a/README.md
+++ b/README.md
@@ -55,8 +55,8 @@ At least the first three fields have to be given. The remaining ones are optiona
To apply the network emulation only to a limit stream of packets, you can use the `mark` tool.
- ./netem -m 0xCD dist load < measurements.dat
- sudo LD_PRELOAD=${PWD}/mark.so MARK=0xCD ping google.de
+ ./netem -m 0xBABE dist load < measurements.dat
+ sudo LD_PRELOAD=${PWD}/mark.so MARK=0xBABE netcat google.de 80
This tool uses the dynamic linker to hook into the `socket()` wrapper-function of libc (see `mark.c`).
Usually, the hook will simply call the original `socket(2)` syscall for non-AF_NET sockets.
@@ -64,9 +64,18 @@ But for AF_INET sockets, the hook will additionally call `setsockopt(sd, SOL_SOC
Later on, the `netem` tool will use combination of the classfull `prio` qdisc and the `fw` classifier to limit the network emulation only to the _marked_ application (see use case 5, below).
-*Note:* Please make sure the specify the environmental variables after the sudo command!
-This is necessary, as `ping` is a SUID program.
-The dynamic linker strips certain enviromental variables (as `LD_PRELOAD`) for security reasons!
+*Note:* There are two pittfalls when using this approach:
+
+- Make sure to specify the environmental variables after the sudo command! This is necessary, as `ping` is a SUID program. The dynamic linker strips certain enviromental variables (as `LD_PRELOAD`) for security reasons when privileges are elevated.
+- Setting the packet mark requires CAP_NET_ADMIN privs. Therefore you must start the application as root. Unfortunately, some applications also drop those privs quite early (ping is an example which luckily has an `-m` option).
+
+Alternatively you can set the mark using netfilter:
+
+ iptables -t mangle -I OUTPUT -d 8.8.8.8 --set-mark 0xBABE -j MARK
+
+Or, the `tc-cgroup.sh` script which uses a special priority for a certain cgroup:
+
+ ./tc-cgroup ping google.de
###### Use case 5: Show the current Traffic Controller setup
@@ -167,4 +176,4 @@ This program is free software: you can redistribute it and/or modify it under th
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the GNU General Public License for more details.
-You should have received a copy of the GNU General Public License along with this program. If not, see .
\ No newline at end of file
+You should have received a copy of the GNU General Public License along with this program. If not, see .