I will try to keep this simple. At the the moment I have a Cisco 2800 router acting as SIP Gateway. The router also terminates a PRI (QSIG) link from an old Siemens Hicom PBX. I can make and place calls from the Hicom and into the SIP cloud and vi...
You could also use CBAC - which was the precursor to ZBF - potentially easier to configure - but slightly less flexible.
In this situation you apply inbound ACL denying all traffic. CBAC support self generated traffic now. Then apply inspection outb...
What information can you get from the far end - I assume it's not in your control. Ideally you want to see the configuration.
In addition you would want see their ARP cache. Is the media a cloud?
Talking from someone who has taken the exam four times and failed I understand the sacrifices.
Looking back on stress is a big part of it. Particularly on the first two attempts where I was no where near ready. Something nasty happened on my forth at...
Try this
ip access extended ACL-INTERNET-IN permit tcp 11.11.11.16 0.0.0.15 host <OUTSIDE-INTERFACE-ADDRESS> eq 22 23 deny tcp any any eq 22 23 permit ip any any
First line allows you to manage the router.
Second line denies all other telnet or SSH.
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