Disabling dns cache with dns-ttl doesn't seem to work

[vsmart-duo]

Hi, thanks for building vegeta, it's been very useful for my testing!

Version and Runtime

Version: 12.11.1                                                                             
Commit:                                                                                      
Runtime: go1.21.3 darwin/arm64                                                               
Date: 2023-10-02T09:03:39Z

Expected Behaviour

I'm using vegeta to send traffic to a host like my-server.com.
In the background during the load test, I'm updating the dns record for my-server.com to another host.
Once dig resolves to the new server I expected vegeta (30s to 1min after the update) to send traffic to the new server.
TTL on the records is 60 seconds.

Actual Behaviour

No matter what I input to the dns-ttl flag (-1 for disabled, 1s etc), the old record seems to be cached by vegeta. It only updates after 7-8minutes. Until then the old server receives no or very few requests from vegeta.

Steps to Reproduce

echo "GET http:/my-server.com" | vegeta attack -duration=1800s -rate=30 -dns-ttl=-1 | tee results.bin | vegeta report

• Update my-sever.com record during the test
• Observe vegeta only send traffic to first server.

Additional Context

Thank you!