Category: Networking
Fix Wireshark Permission Error on macOS: ChmodBPF Guide
If you see the error “The capture session could not be initiated on the device “en0” (You don’t have permission to capture on that device)” when trying to start a pcap on wireshare you can try installing ChmodBPF; but I suspect you will need to follow the steps below:
Read more →nmap Vulners Script: Quick Vulnerability Scanning on macOS
This is a very short post to help anyone quickly setup vulnerability checking for a site they own (and have permission to scan). I like the vulners scripts as they cover a lot of basic ground quickly with one script.
Read more →Mac Terminal: Scan TLS Certificates with NMAP and SSLScan
The below script will give you basic information on a websites certificate: NMAP is provides a simple way to get a list of available ciphers from a host website / server. Additionally, nmap provides a strength rating of strong, weak, or unknown for each available cipher. First, download the ssl-enum-ciphers.nse nmap script (explanation here). Then from the same […]
Read more →Fix DNS Issues Using dig and whois on Mac OS X
When debugging DNS issues its important to verify the local DNS response with the authoritive DNS nameserver. With dig we can directly query the authoritative name servers for a domain, these are the DNS servers that hold the authoritative records for the domains DNS zone; the source of truth. If a correct response is received […]
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Find MTU Between Two Hosts Using Ping Do-Not-Fragment
If you have ever tried to use jumbo packets, or trace a weird slowness on the network – one of the things that frequently comes up is packet fragmentation. This is basically where a source machine is sending bigger packets than can be consumed along its pathway to a destination machine. This means the packets […]
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Find Max MTU Size on Mac OS X Using Ping (No Fragmentation)
If you have ever tried to use jumbo packets, or trace a weird slowness on the network – one of the things that frequently comes up is packet fragmentation. This is basically where a source machine is sending bigger packets than can be consumed along its pathway to a destination machine. This means the packets […]
Read more →Scan SSL/TLS Ciphers With nmap and sslscan on macOS
To retrieve a list of the SSL/TLS cipher suites a particular website offers you can either use sslscan or nmap alternatively you can just use nmap (note: i use “-e en0” to bypass zscaler): Another variant (including cert dates, again “-e en0” is used to bypass zscaler):
Read more →curl Command: Get HTTP Response Headers in Terminal
Web devs need to know the http headers their apps/webpages. This can be easily achieved using a browser plugin for Chrome or Firefox. But I prefer to use the command terminal, and curl makes this really easy.
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DNS Lookup with DIG: Query Records & Trace Resolution
DIG is an awesome command line utility to explore DNS. Below is a quick guide to get you started. Query Specific Name Server By default, if no name server is specified, dig will use the servers listed in /etc/resolv.conf file. To view the default server use: You can override the name server against which the query will be executed, […]
Read more →Mac: Find Open Ports and IP Addresses with lsof & netstat
Below is a dump of examples of doing pretty much the same thing differently. I mostly use netstat and lsof, coupled with some bash scripts. You can argue that this is overkill, but below is a simple bash function that you can paste into terminal and call it whenever you want to see which application/process […]
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