search

blechschmidt / massdns

A high-performance DNS stub resolver for bulk lookups and reconnaissance (subdomain enumeration)
GNU General Public License v3.0
3.08k stars 460 forks source link

It takes lot of time and -c 200 count does not cover 100000 entry .... #20

Closed yam23 closed 6 years ago

yam23 commented 6 years ago

It could be very dump question or some mistake with my configuration of vmware instant .... I apologies in advance for that ....

It takes lot of time on my machine ....I used it on Kali-Linux-Light-2017.1-vm-amd64 , when I tried domain list of100000 it does not complete with 200 count also ... i used below command .... ./subbrute.py names.txt example.com | ./bin/massdns -r resolvers.txt -t A -a -o -w results.txt - It does not complete even 15000 checks ..... and it takes less than a minute with below command for 50000 checks , ./subbrute.py names.txt example.com | ./bin/massdns -r resolvers.txt -t A -a -o -c 100 -w results.txt - It covers 24000 entry in 4-5 mintues ..... my ultimate aim is to use all.txt prepared by Jason(awesome presentation on LevelUp) , I came to know from there about massdns.....

I have allocated 8 cores and 3 gb RAM....It never crosses even 6 digit check.....I even tried with -c 200 count but it takes 14-15 minutes and completes with 75K entry....

Am i missing some configuration of enabling parallel threading ?

Thanks,

blechschmidt commented 6 years ago

MassDNS requires a decent amount of upload bandwidth in order for the default configuration to work. It is single-threaded because it is designed for scenarios in which the network is the bottleneck.

In order to obtain more reliable results, try adjusting the size of the internal hash map using the -s parameter which controls the amount of concurrent lookups. Depending on your upload bandwidth, 1000 might be a reasonable value if you are using MassDNS with a conventional home internet connection. However, MassDNS is mainly designed to be run on servers with a high bandwidth like the 10$/month DigitalOcean VPS instance.

Nonetheless, the VM could be a bottleneck, too.

I will try to improve the README soon because it lacks an explanation of how MassDNS works internally and I think the correlation between the -s parameter and performance is not quite obvious.

yam23 commented 6 years ago

You are awesome !! I was suspecting same as my network was getting slow when I was running the same, I need to find out some VPS instance or divide large domain files and run massdns on chuncks during night with masscan after that ....

I will explore -s parameter as you suggested , hopefully this weekend ....

Thanks for Detail Explanation !!

Cheers, Anis

On Tue, Aug 15, 2017 at 5:58 PM, B. Blechschmidt notifications@github.com wrote:

MassDNS requires a decent amount of upload bandwidth in order for the default configuration to work. It is single-threaded because it is designed for scenarios in which the network is the bottleneck.

In order to obtain more reliable results, try adjusting the size of the internal hash map using the -s parameter which controls the amount of concurrent lookups. Depending on your upload bandwidth, 1000 might be a reasonable value if you are using MassDNS with a conventional home internet connection. However, MassDNS is mainly designed to be run on servers with a high bandwidth like the 10$/month DigitalOcean VPS instance.

Nonetheless, the VM could be a bottleneck, too.

I will try to improve the README soon because it lacks an explanation of how MassDNS works internally and I think the correlation between the -s parameter and performance is not quite obvious.

— You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub https://github.com/blechschmidt/massdns/issues/20#issuecomment-322621003, or mute the thread https://github.com/notifications/unsubscribe-auth/AdjkU7N-aQEu5Goez3ad5tjeBisgFZVAks5sYjCKgaJpZM4O13Py .