Something

sed -e '/^#/d' -e 's/^ *//' -e 's/ *$//' -e 's/ *: */:/g' router.db |
   sort -u > routers.db
cut -d: -f1,2 routers.db > routers.all.new
if [ ! -f routers.all ] ; then touch routers.all; fi
diff -u -4 routers.all routers.all.new > /dev/null 2>&1; RALL=$?
perl -F: -ane '{($F[0] =~ tr@A-Z@a-z@,print $_)
    if ($F[2] !~ /^up$/i);}' routers.db > routers.down.new
if [ ! -f routers.down ] ; then touch routers.down; fi
diff -u -4 routers.down routers.down.new > /dev/null 2>&1; RDOWN=$?
perl -F: -ane '{($F[0] =~ tr@A-Z@a-z@,print "$F[0]:$F[1]\n")
    if ($F[2] =~ /^up$/i);}' routers.db > routers.up.new
if [ ! -f routers.up ] ; then touch routers.up; fi
diff -u -4 routers.up routers.up.new > /dev/null 2>&1; RUP=$?