Linux – snmp linux timezone

Short answer: you can't. Ports below 1024 can be opened only by root. As per comment - well, you can, using CAP_NET_BIND_SERVICE, but that approach, applied to java bin will make any java program to be run with this setting, which is undesirable, if not a security risk.

The long answer: you can redirect connections on port 80 to some other port you can open as normal user.

Run as root:

# iptables -t nat -A PREROUTING -p tcp --dport 80 -j REDIRECT --to-port 8080

As loopback devices (like localhost) do not use the prerouting rules, if you need to use localhost, etc., add this rule as well (thanks @Francesco):

# iptables -t nat -I OUTPUT -p tcp -d 127.0.0.1 --dport 80 -j REDIRECT --to-ports 8080

NOTE: The above solution is not well suited for multi-user systems, as any user can open port 8080 (or any other high port you decide to use), thus intercepting the traffic. (Credits to CesarB).

EDIT: as per comment question - to delete the above rule:

# iptables -t nat --line-numbers -n -L

This will output something like:

Chain PREROUTING (policy ACCEPT)
num  target     prot opt source               destination         
1    REDIRECT   tcp  --  0.0.0.0/0            0.0.0.0/0           tcp dpt:8080 redir ports 8088
2    REDIRECT   tcp  --  0.0.0.0/0            0.0.0.0/0           tcp dpt:80 redir ports 8080

The rule you are interested in is nr. 2, so to delete it:

# iptables -t nat -D PREROUTING 2

When you snmpwalk a device using the net-snmp snmpwalk tool, it will not by default return anything in the enterprise MIBs, such as UCD-SNMP.

Enterprise MIBs are all the OIDs that start with .1.3.6.1.4.1.

You can work around this by specifying where on the OID tree to start walking, instead of returning the default parts of the tree

  snmpwalk -v2c -cpublic 10.8.0.1 .1.3.6.1.4.1

would walk the tree starting with 'enterprises.', which would return the UCD-SNMP-MIB with all that good information that you want.

You can also do

  snmpwalk -v2c -cpublic 10.8.0.1 .1

which says "start at .1" which is the top of the OID tree, and will return everything.

Now, many of the OIDs won't be translated into names. You have to ask snmpwalk to turn OIDs into names by parsing all of the non-default MIBs, you do that by adding '-mALL' to the command line

  snmpwalk -v2c -cpublic -mALL 10.8.0.1 .1

will return everything, with OIDs turned to names (where you have a copy of the MIB file in one of the default MIB directories).

HTH