Launch Curl Against a Domain

Case

Spawn a command that resolves hostnames and monitor its traffic, echoing test_sub_curl_domain_program.sh.
Demonstrate capturing DNS-resolved HTTP requests for external domains while ptcpdump handles process attribution.
Verify that a specific application correctly resolves domain names and connects to the intended IP addresses.
Troubleshoot DNS resolution failures for applications by observing the entire DNS lookup and connection process.
Monitor outbound connections to external domains initiated by a specific command or script.

Command

sudo ptcpdump -i any -v -- curl -m 10 https://ubuntu.com

ptcpdump invokes curl, captures the HTTP exchange (including SYN packets toward the resolved IP), and records metadata showing the full command line curl -m 10 ubuntu.com. Useful for capturing short-lived runs without missing the initial handshake.

Output Example

15:08:28.079227 lo Out IP (tos 0x0, ttl 64, id 13848, offset 0, flags [DF], proto UDP (17), length 67)
    127.0.0.1.37308 > 127.0.0.53.53: 20673+ [1au] A? ubuntu.com. (39)
    Process (pid 254949, cmd /usr/bin/curl, args curl -m 10 https://ubuntu.com)
    User (uid 0)
    ParentProc (pid 254941, cmd ptcpdump, args ptcpdump -- curl -m 10 https://ubuntu.com)
15:08:28.110391 lo Out IP (tos 0x0, ttl 1, id 47265, offset 0, flags [DF], proto UDP (17), length 115)
    127.0.0.53.53 > 127.0.0.1.37308: 20673 3/0/1 A 185.125.190.29, A 185.125.190.20, A 185.125.190.21 (87)
    Process (pid 254949, cmd /usr/bin/curl, args curl -m 10 https://ubuntu.com)
    User (uid 0)
    ParentProc (pid 254941, cmd ptcpdump, args ptcpdump -- curl -m 10 https://ubuntu.com)
...
15:08:28.110417 lo In IP (tos 0x0, ttl 1, id 47265, offset 0, flags [DF], proto UDP (17), length 115)
    127.0.0.53.53 > 127.0.0.1.37308: 20673 3/0/1 A 185.125.190.29, A 185.125.190.20, A 185.125.190.21 (87)
    Process (pid 254949, cmd /usr/bin/curl, args curl -m 10 https://ubuntu.com)
    User (uid 0)
    ParentProc (pid 254941, cmd ptcpdump, args ptcpdump -- curl -m 10 https://ubuntu.com)
...
15:08:28.440246 ens33 Out IP (tos 0x0, ttl 64, id 18470, offset 0, flags [DF], proto TCP (6), length 60)
    10.0.2.15.33824 > 185.125.190.29.443: Flags [S], cksum 0x83d8, seq 1966522591, win 64240, options [mss 1460,sackOK,TS val 2720366192 ecr 0,nop,wscale 7], length 0
    Process (pid 254949, cmd /usr/bin/curl, args curl -m 10 https://ubuntu.com)
    User (uid 0)
    ParentProc (pid 254941, cmd ptcpdump, args ptcpdump -- curl -m 10 https://ubuntu.com)