change formatting

input examples are now given as

```bash
input $ARG1
```

While outputs use md's '> ' sign as a quote.

networking/iptables.md

@@ -8,7 +8,9 @@ This is a basic Linux firewall program.
 
 Look at your firewalls:
 
-> iptables -L
+```bash
+iptables -L
+```
 
 We see the output of input, output and forwarding rules.
 
@@ -16,19 +18,27 @@ We see the output of input, output and forwarding rules.
 
 I don't need any forwarding, so I'm going to drop all forwarding:
 
-> iptables -P FORWARD DROP
+```bash
+iptables -P FORWARD DROP
+```
 
 # Input
 
 Let's 'A'dd, or 'A'ppend a rule with -A.  Let's drop all input from a nearby IP 
 
-> iptables -A INPUT -s 192.168.0.23 -j DROP
+```bash
+iptables -A INPUT -s 192.168.0.23 -j DROP
+```
 
 Or we can block all input from a particular port on the full Network.
 
-> iptables -A INPUT -s 192.168.0.0/24 -p tcp --destination-port 25 -j DROP
+```bash
+iptables -A INPUT -s 192.168.0.0/24 -p tcp --destination-port 25 -j DROP
+```
 
-> iptables -A INPUT --dport 80 -j ACCEPT
+```bash
+iptables -A INPUT --dport 80 -j ACCEPT
+```
 
 
 This allows http traffic to an Apache web server over port 80.
@@ -37,11 +47,15 @@ However, rules are accepted in order - so a packet cannot be rejected and then a
 
 To delete rule 2 from the INPUT chain:
 
-> iptables -D INPUT 3
+```bash
+iptables -D INPUT 3
+```
 
 Alternatively, you can 'I'nsert a rule at the start, rather than 'A'ppending it.
 
-> iptables -I INPUT -s 192.168.0.13 DROP
+```bash
+iptables -I INPUT -s 192.168.0.13 DROP
+```
 
 # Catchalls
 
@@ -53,7 +67,9 @@ The -j flag accepts ACCEPT/REJECT/DROP.  The last two are identical except that
 
 Flush all existing rules with:
 
-> iptables -F
+```bash
+iptables -F
+```
 
 
 # Examples