Might have given me a clue, though.
How does your /etc/nsswitch.conf look like and what's the content of /etc/hosts? Preferably of both systems, let's see if something is different.
/etc/nsswitch.conf on working system: passwd: files nis systemd shadow: files nis group: files nis systemd
#hosts: db files nisplus nis dns hosts: files dns nisplus nis mdns4_minimal myhostname mymachines
# Example - obey only what nisplus tells us... #services: nisplus [NOTFOUND=return] files #networks: nisplus [NOTFOUND=return] files #protocols: nisplus [NOTFOUND=return] files #rpc: nisplus [NOTFOUND=return] files #ethers: nisplus [NOTFOUND=return] files #netmasks: nisplus [NOTFOUND=return] files
bootparams: nisplus [NOTFOUND=return] files
ethers: files netmasks: files networks: files protocols: files rpc: files services: files
#netgroup: files nis
publickey: nisplus
automount: files nis aliases: files nisplus
/etc/nsswitch.conf on non-working system: passwd: files nis systemd shadow: files nis group: files nis systemd
#hosts: db files nisplus nis dns hosts: files nis mdns4_minimal [NOTFOUND=return] dns myhostname
# Example - obey only what nisplus tells us... #services: nisplus [NOTFOUND=return] files #networks: nisplus [NOTFOUND=return] files #protocols: nisplus [NOTFOUND=return] files #rpc: nisplus [NOTFOUND=return] files #ethers: nisplus [NOTFOUND=return] files #netmasks: nisplus [NOTFOUND=return] files
bootparams: nisplus [NOTFOUND=return] files
ethers: files netmasks: files networks: files protocols: files rpc: files services: files
netgroup: files nis
publickey: nisplus
#automount: files nis sss automount: files nis aliases: files nisplus
/etc/hosts on working system: 127.0.0.1 localhost.localdomain localhost.localdomain localhost4 localhost4.localdomain4 localhost erdos ::1 localhost.localdomain localhost.localdomain localhost6 localhost6.localdomain6 localhost erdos 150.108.64.52 dsm.dsm.fordham.edu dsm
/etc/hosts on non-working system: 127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4 #::1 localhost localhost.localdomain localhost6 localhost6.localdomain6
150.108.64.57 sobolev.dsm.fordham.edu sobolev 150.108.64.65 mandelbrot.dsm.fordham.edu mandelbrot 150.108.64.52 dsm.dsm.fordham.edu dsm
Maybe the system's short name or FQDN is not mapped to an address correctly?
I don't see where this could be happening but there are some differences from the 2 files you asked about. Note that the ipv6 option is commented OUT on the non-working system but could that be a reason? You can also see the hosts entry n in /etc/nsswitch.conf is slightly different.