Eruv: Walled or Stringed

There are two general kinds of eruv's that are acceptable, one walled and one surrounded by a string. The potential issue with the stringed eruv is that it must be checked regularly. It is important to determine that the eruv stand up on a regular basis so that it is very reliable. If the eruv falls down frequently, one should determine whether they should rely upon it until the problems are resolved and review the laws of eruv.