Originally Posted by shaggybear
How large an IP block would I need in order to not be filtered out by other networks?
Are there considerations other than size, and objectionable traffic like spam, that are important ?
Filtered as in what way? As in prefix filters preventing you from announcing IP blocks that don't belong to you?
No one is going to blindly open a filter to anyone. Its the networks responsibility to maintain proper filtering on all links. Unless your a Tier1 or Tier2 network and even then on tier2 networks they still might filter you.