firewall rules for core router

[Sami Halabi]

that exactly what i need, all address space in use is public

Thank sgain,
Sami
בתאריך 8 בינו 2013 21:11, מאת "Julian Elischer" <julian at freebsd.org>:
>
> On 1/8/13 10:35 AM, Sami Halabi wrote:
>>
>> Thank you for your response.
>> about fwd:
>> w.x.y.z is a router.. do i still need something? will it forward the
packet correctly?
>
>
> It will send them to where-ever it thinks they were originally sent to.
>
>
>> בתאריך 8 בינו 2013 19:02, מאת "Julian Elischer" <julian at freebsd.org>:
>>>
>>> On 1/8/13 6:44 AM, Sami Halabi wrote:
>>>>
>>>> Anh one?
>>>> בתאריך 7 בינו 2013 18:09, מאת "Sami Halabi" <sodynet1 at gmail.com>:
>>>>
>>>>> Hi,
>>>>> i have a core router that i want to enable firewall on it.
>>>>> is these enough for a start:
>>>>>
>>>>> ipfw add 100 allow all from any to any via lo0
>>>>> ipfw add 25000 allow all from me to any
>>>>> ipfw add 25100 allow ip from "table(7)" to me dst-port 179
>>>>> #ipfw add 25150 allow ip from "table(7)" to me
>>>>> ipfw add 25200 allow ip from "table(8)" to me dst-port 161
>>>>> #ipfw add 25250 allow ip from "table(8)" to me
>>>>> ipfw add 25300 allow all from any to me dst-port 22
>>>>> ipfw add 25400 allow icmp from any to any
>>>>> ipfw add 25500 deny all from any to me
>>>>> ipfw add 230000 allow all from any to any
>>>>>
>>>>> while table-7 are my BGP peers, table-8 my NMS.
>>>>>
>>>>> do i need to open anything more? any routing protocol/forwarding plan
>>>>> issues?
>>>
>>> I see nothing wrong.. it'll do what you want it that's what you want :-)
>>>
>>> you trust yourself
>>> and you allow ssh and BGP and NMS incoming
>>> and icmp everywhere
>>> but you won't be able to start outgoing ssh sessions because the return
packets will be coming back to ephemeral ports.
>>>
>>> several ways to get around htat , like using keep-state, or just
blocking INIT packets differently (see "established")
>>>
>>>>>
>>>>>
>>>>> another thing:
>>>>> i plan to add the following rule
>>>>> ipfw add 26000 fwd w.x.y.z all from a.b.c.0/24 to any
>>>>>
>>>>> will this work?, does my peer (ISP, with Cisco/Juniper equipment)
needs to
>>>>> do anything else?
>>>
>>>
>>> w.x.y.z needs to know to accept those packets as they will still be
aimed at w.x.y.z. (dest addr)
>>> if this machine is w.x.y.z then this command will achieve that.
>>> otherwise you will need to either have a 'fwd' rule on w.x.y.z. (if
it's freebsd) or to change the packet,
>>> which will require you run it through natd. (or use a nat rule)
>>>
>>>
>>>>> Thanks in advance,
>>>>>
>>>>> --
>>>>> Sami Halabi
>>>>> Information Systems Engineer
>>>>> NMS Projects Expert
>>>>> FreeBSD SysAdmin Expert
>>>>>
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>>>>
>>>>
>>>
>