Lymph nodes can get swollen when they are fighting off germs in your body. This is a good thing, as it is killing the germs and disposing of them.
Using lymph stimulant essential oils like Cedarwood and citrus essential oils by rolling them on can help stimulate the lymph and help encourage the lymph nodes to drain.
As the lymph system doesn't have its own pump, and some of us are not as active as we should be, using both essential oils and gentle massage together can help the lymph do its job. Apply the massage blend and gently massage. Don't apply too much pressure to the lymph nodes if they are tender. Here is a good video showing you how: Self Lymphatic Drainage Massage.