add bpftool ans some docs

Dockerfile

@@ -26,6 +26,7 @@ RUN set -ex; \
         btop \
         bash \
         bash-completion \
+        bpftool \
         bcc-tools \
         bind-tools \
         bird \

README.md

@@ -98,6 +98,7 @@ some with some sample use-cases.
 - btop: Resource monitor
 - bcc: A toolkit for creating efficient kernel tracing and manipulation programs
 - bcc-tools: Command line tools for BPF Compiler Collection (BCC)
+- bpftool - Linux kernel bpf manipulation tool.
 - bpftrace: High-level tracing language for Linux eBPF
 - bpftrace-tools: High-level tracing language for Linux eBPF (tools)
 - ctop: Top-like interface for container metrics
@@ -418,6 +419,25 @@ Connection to service-a 8080 port [tcp/http-alt] succeeded!
 
 ```
 
+## hping
+
+Purpose: Packet generator capable of doing quite a lot.
+In terms of troubleshooting, handy to test network latency where ICMP does not work.
+
+Example : Test network latency from the container to a remote host on a specific port
+```
+🐳  → docker run -it --net container:perf-test-a.1.bil2mo8inj3r9nyrss1g15qav nicolaka/netshoot hping -S -c 5 google.com -p 80
+HPING google.com (eth0 74.125.201.139): S set, 40 headers + 0 data bytes
+len=44 ip=74.125.201.139 ttl=62 id=40057 sport=80 flags=SA seq=0 win=65504 rtt=42.8 ms
+len=44 ip=74.125.201.139 ttl=62 id=40058 sport=80 flags=SA seq=1 win=65504 rtt=44.6 ms
+len=44 ip=74.125.201.139 ttl=62 id=40059 sport=80 flags=SA seq=2 win=65504 rtt=43.1 ms
+len=44 ip=74.125.201.139 ttl=62 id=40060 sport=80 flags=SA seq=3 win=65504 rtt=37.2 ms
+len=44 ip=74.125.201.139 ttl=62 id=40061 sport=80 flags=SA seq=4 win=65504 rtt=34.6 ms
+--- google.com hping statistic ---
+5 packets tramitted, 5 packets received, 0% packet loss
+round-trip min/avg/max = 34.6/40.5/44.6 ms
+```
+
 ## netgen
 Purpose: `netgen` is a simple [script](netgen.sh) that will generate a packet of data 
 between containers periodically using `netcat`. The generated traffic can be used to