perl -le 'local$/;open F,data;$_=<F>;s/\n//g;while(/<ip-address>(.+?)<\/ip/gi){print $1}'

##</code><code>##

perl -le 'local$/;open F,data;$_=<F>;s/\n//g;while(/<ip-(neigbour|address)>(.+?)<\/ip/gi){print $2}'